Methods, access point and wireless device for optimizing the modulation and coding scheme (MCS) used for exchanging probe request and probe responses between an access point and a wireless device

ABSTRACT

Systems, methods, and devices for wireless communication are provided. In an embodiment, a method of determining a set of communication parameters for a wireless communication includes transmitting, at an access point, one or more frames each including a transmission power indication, receiving, at the access point, a probe request using a first set of communication parameters; and transmitting, at the access point, a probe response using a second set of communication parameters, the second set of communication parameters based on the first set of communication parameters. In some aspects, each of the first and second set of communication parameters define a MCS, which defines a coding rate of the communication.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. provisional application No.61/872,166 filed Aug. 30, 2013, and entitled “METHODS AND SYSTEMS FORHIGH EFFICIENCY COMMUNICATION IN WIRELESS ENVIRONMENTS.” The disclosureof this prior application is considered part of this application, and ishereby incorporated by reference in its entirety.

BACKGROUND

Field

The present application relates generally to wireless communications,and more specifically to systems, methods, and devices for highefficiency wireless communication in dense wireless environments.

Background

In many telecommunication systems, communications networks are used toexchange messages among several interacting spatially-separated devices.Networks may be classified according to geographic scope, which couldbe, for example, a metropolitan area, a local area, or a personal area.Such networks would be designated respectively as a wide area network(WAN), metropolitan area network (MAN), local area network (LAN),wireless local area network (WLAN), or personal area network (PAN).Networks also differ according to the switching/routing technique usedto interconnect the various network nodes and devices (e.g., circuitswitching vs. packet switching), the type of physical media employed fortransmission (e.g., wired vs. wireless), and the set of communicationprotocols used (e.g., Internet protocol suite, SONET (SynchronousOptical Networking), Ethernet, etc.).

Wireless networks are often preferred when the network elements aremobile and thus have dynamic connectivity needs, or if the networkarchitecture is formed in an ad hoc, rather than fixed, topology.Wireless networks employ intangible physical media in an unguidedpropagation mode using electromagnetic waves in the radio, microwave,infra-red, optical, etc. frequency bands. Wireless networksadvantageously facilitate user mobility and rapid field deployment whencompared to fixed wired networks.

However, multiple wireless networks may exist in the same building, innearby buildings, and/or in the same outdoor area. The prevalence ofmultiple wireless networks may cause interference, reduced throughput(e.g., because each wireless network is operating in the same areaand/or spectrum), and/or prevent certain devices from communicating.Thus, improved systems, methods, and devices for communicating whenwireless networks are densely populated are desired.

SUMMARY

The systems, methods, and devices of the invention each have severalaspects, no single one of which is solely responsible for its desirableattributes. Without limiting the scope of this invention as expressed bythe claims which follow, some features will now be discussed briefly.After considering this discussion, and particularly after reading thesection entitled “Detailed Description” one will understand how thefeatures of this invention provide advantages that include improvedcommunications between access points and stations in a wireless network.

One aspect of this disclosure provides a method of determining acommunication rate for a high-efficiency wireless communication. Themethod includes receiving, at an access point, a probe request includinga transmission power indication. The method further includes determininga received transmission power. The method further includes estimating apath-loss based on the transmission power indication and receivedtransmission power. The method further includes transmitting a firstprobe response at a first rate. The method further includes transmittinga second probe response at a second data rate when the access point doesnot receive an acknowledgement to the first probe response within atimeout period, the second data rate being lower than the first rate.

Another aspect of the present disclosure provides a method ofdetermining a communication rate for a high-efficiency wirelesscommunication. The method includes transmitting, at a wireless device, aprobe request including a transmission power indication. The methodfurther includes receiving, from an access point, a probe response ateither a first or second rate, the second rate being lower than thefirst rate. The method further includes transmitting an acknowledgementto the probe response at either the first or second rate based on therate of the probe response.

Another aspect of the present disclosure provides a method ofdetermining a communication rate for a high-efficiency wirelesscommunication. The method includes transmitting, at an access point, oneor more frames each including a transmission power indication. Themethod further includes receiving a probe request at a first rate. Themethod further includes transmitting a probe response at a second rate,the second rate being a function of the first rate.

Another aspect of the present disclosure provides a method ofdetermining a communication rate for a high-efficiency wirelesscommunication. The method includes receiving, at a wireless device, oneor more frames from an access point, each frame including a transmissionpower indication. The method further includes estimating a link qualitybased on the transmission power indication. The method further includestransmitting a probe request at a first rate compatible with theestimated link quality. The method further includes receiving a proberesponse at a second rate, the second rate being a function of the firstrate.

Another aspect of the present disclosure provides a method ofhigh-efficiency wireless communication. The method includes receiving,at an access point, a probe request. The method further includesgenerating a probe response in response to the probe request. The methodfurther includes conditionally including neighbor report information inthe probe response based on an indication or absence of an indication inthe probe request. The method further includes transmitting the proberesponse to a wireless device.

Another aspect of the present disclosure provides a method ofhigh-efficiency wireless communication. The method includes determining,at a wireless device, whether neighborhood report information is stored.The method further includes transmitting a probe request conditionallyincluding a request for neighbor report information based on saiddetermining. The method further includes receiving a probe response. Theprobe response includes the neighbor report information when the proberequest includes the request for neighbor report information.

Another aspect of the present disclosure provides a method ofhigh-efficiency wireless communication. The method includes receiving,at an access point, a probe request including shared wireless devicestate information. The method further includes storing the sharedwireless device state information for at least a timeout period. Themethod further includes transmitting a probe response indicating thetimeout period. The method further includes receiving an associationrequest omitting the wireless device state information within thetimeout period.

Another aspect of the present disclosure provides a method ofhigh-efficiency wireless communication. The method includestransmitting, at a wireless device, a probe request including sharedwireless device state information. The method further includes receivinga probe response indicating a timeout period. The method furtherincludes transmitting an association request omitting the wirelessdevice state information within the timeout period.

Another aspect of the present disclosure provides a method ofhigh-efficiency wireless communication. The method includes receiving,at an access point, a probe request from a wireless device. The methodfurther includes transmitting a probe response including shared accesspoint state information. The method further includes receiving anassociation request including an indication that the wireless device hasstored the shared access point state information. The method furtherincludes transmitting an association response omitting the shared accesspoint state information.

Another aspect of the present disclosure provides a method ofhigh-efficiency wireless communication. The method includestransmitting, at a wireless device, a probe request to an access point.The method further includes receiving a probe response including sharedaccess point state information. The method further includes storing theshared access point state information. The method further includestransmitting an association request including an indication that thewireless device has stored the shared access point state information.The method further includes receiving an association response omittingthe shared access point state information.

Another aspect of the present disclosure provides an apparatus fordetermining a communication rate for a high-efficiency wirelesscommunication. The apparatus includes means for receiving a proberequest including a transmission power indication. The apparatus furtherincludes means for determining a received transmission power. Theapparatus further includes means for estimating a path-loss based on thetransmission power indication and received transmission power. Theapparatus further includes means for transmitting a first probe responseat a first rate. The apparatus further includes means for transmitting asecond probe response at a second rate when the access point does notreceive an acknowledgement to the first probe response within a timeoutperiod, the second rate being lower than the first rate.

Another aspect of the present disclosure provides an apparatus fordetermining a communication rate for a high-efficiency wirelesscommunication. The apparatus includes means for transmitting a proberequest including a transmission power indication. The apparatus furtherincludes means for receiving, from an access point, a probe response ateither a first or second rate, the second rate being lower than thefirst rate. The apparatus further includes means for transmitting anacknowledgement to the probe response at either the first or second ratebased on the rate of the probe response.

Another aspect of the present disclosure provides an apparatus fordetermining a communication rate for a high-efficiency wirelesscommunication. The apparatus includes means for transmitting one or moreframes each including a transmission power indication. The apparatusincludes means for receiving a probe request at a first rate. Theapparatus further includes means for transmitting a probe response at asecond rate, the second rate being a function of the first rate.

Another aspect of the present disclosure provides an apparatus fordetermining a communication rate for a high-efficiency wirelesscommunication. The apparatus includes means for receiving one or moreframes from an access point, each frame including a transmission powerindication. The apparatus further includes means for estimating a linkquality based on the transmission power indication. The apparatusfurther includes means for transmitting a probe request at a first ratecompatible with the estimated link quality. The apparatus furtherincludes means for receiving a probe response at a second rate, thesecond rate being a function of the first rate.

Another aspect of the present disclosure provides an apparatus forhigh-efficiency wireless communication. The apparatus further includesmeans for receiving a probe request. The apparatus further includesmeans for generating a probe response in response to the probe request.The apparatus further includes means for conditionally includingneighbor report information in the probe response based on an indicationor absence of an indication in the probe request. The apparatus furtherincludes means for transmitting the probe response to a wireless device.

Another aspect of the present disclosure provides an apparatus forhigh-efficiency wireless communication. The apparatus includes means fordetermining whether neighborhood report information is stored. Theapparatus further includes means for transmitting a probe requestconditionally including a request for neighbor report information basedon said determining. The apparatus further includes means for receivinga probe response. The probe response includes the neighbor reportinformation when the probe request includes the request for neighborreport information.

Another aspect of the present disclosure provides an apparatus forhigh-efficiency wireless communication. The apparatus includes means forreceiving a probe request including shared wireless device stateinformation. The apparatus further includes means for storing the sharedwireless device state information for at least a timeout period. Theapparatus further includes means for transmitting a probe responseindicating the timeout period. The apparatus further includes receivingan association request omitting the wireless device state informationwithin the timeout period.

Another aspect of the present disclosure provides an apparatus forhigh-efficiency wireless communication. The apparatus includes means fortransmitting a probe request including shared wireless device stateinformation. The apparatus further includes means for receiving a proberesponse indicating a timeout period. The apparatus further includesmeans for transmitting an association request omitting the wirelessdevice state information within the timeout period.

Another aspect of the present disclosure provides an apparatus forhigh-efficiency wireless communication. The apparatus includes means forreceiving a probe request from a wireless device. The apparatus furtherincludes means for transmitting a probe response including shared accesspoint state information. The apparatus further includes means forreceiving an association request including an indication that thewireless device has stored the shared access point state information.The apparatus further includes means for transmitting an associationresponse omitting the shared access point state information.

Another aspect of the present disclosure provides an apparatus forhigh-efficiency wireless communication. The apparatus includes means fortransmitting a probe request to an access point. The apparatus furtherincludes means for receiving a probe response including shared accesspoint state information. The apparatus further includes means forstoring the shared access point state information. The apparatus furtherincludes means for transmitting an association request including anindication that the wireless device has stored the shared access pointstate information. The apparatus further includes means for receiving anassociation response omitting the shared access point state information.

Another aspect of the present disclosure provides an apparatusconfigured to determine a communication rate for a high-efficiencywireless communication. The apparatus includes a receiver configured toreceive a probe request including a transmission power indication. Theapparatus further includes a processor configured to determine areceived transmission power. The processor is further configured toestimate a path-loss based on the transmission power indication andreceived transmission power. The apparatus includes a transmitterconfigured to transmit a first probe response at a first rate. Thetransmitter is further configured to transmit a second probe response ata second rate when the access point does not receive an acknowledgementto the first probe response within a timeout period, the second ratebeing lower than the first rate.

Another aspect of the present disclosure provides an apparatusconfigured to determine a communication rate for a high-efficiencywireless communication. The apparatus includes a transmitter configuredto transmit a probe request including a transmission power indication.The apparatus further includes a receiver configured to receive, from anaccess point, a probe response at either a first or second rate, thesecond rate being lower than the first rate. The transmitter is furtherconfigured to transmit an acknowledgement to the probe response ateither the first or second rate based on the rate of the probe response.

Another aspect of the present disclosure provides an apparatusconfigured to determine a communication rate for a high-efficiencywireless communication. The apparatus includes a transmitter configuredto transmit one or more frames each including a transmission powerindication. The apparatus further includes a receiver configured toreceive a probe request at a first rate. The transmitter is furtherconfigured to transmit a probe response at a second rate, the secondrate being a function of the first rate.

Another aspect of the present disclosure provides an apparatusconfigured to determine a communication rate for a high-efficiencywireless communication. The apparatus includes a receiver configured toreceive one or more frames from an access point, each frame including atransmission power indication. The apparatus further includes aprocessor configured to estimate a link quality based on thetransmission power indication. The apparatus further includes atransmitter configured to transmit a probe request at a first ratecompatible with the estimated link quality. The receiver is furtherconfigured to receive a probe response at a second rate, the second ratebeing a function of the first rate.

Another aspect of the present disclosure provides an apparatusconfigured to communicate in a high-efficiency wireless communicationnetwork. The apparatus includes a receiver configured to receive a proberequest. The apparatus further includes a processor configured togenerate a probe response in response to the probe request. Theprocessor is further configured to conditionally include neighbor reportinformation in the probe response based on an indication or absence ofan indication in the probe request. The apparatus further includes atransmitter configured to transmit the probe response to a wirelessdevice.

Another aspect of the present disclosure provides an apparatusconfigured to communicate in a high-efficiency wireless communicationnetwork. The apparatus includes a processor configured to determinewhether neighborhood report information is stored. The apparatus furtherincludes a transmitter configured to transmit a probe requestconditionally including a request for neighbor report information basedon said determine. The apparatus further includes a receiver configuredto receive a probe response. The probe response includes the neighborreport information when the probe request includes the request forneighbor report information.

Another aspect of the present disclosure provides an apparatusconfigured to communicate in a high-efficiency wireless communicationnetwork. The apparatus includes a receiver configured to receive a proberequest including shared wireless device state information. Theapparatus further includes a memory configured to store the sharedwireless device state information for at least a timeout period. Theapparatus further includes a transmitter configured to transmit a proberesponse indicating the timeout period. The receiver is furtherconfigured to receive an association request omitting the wirelessdevice state information within the timeout period.

Another aspect of the present disclosure provides an apparatusconfigured to communicate in a high-efficiency wireless communicationnetwork. The apparatus includes a transmitter configured to transmit aprobe request including shared wireless device state information. Theapparatus further includes a receiver configured to receive a proberesponse indicating a timeout period. The transmitter is furtherconfigured to transmit an association request omitting the wirelessdevice state information within the timeout period.

Another aspect of the present disclosure provides an apparatusconfigured to communicate in a high-efficiency wireless communicationnetwork. The apparatus includes a receiver configured to receive a proberequest from a wireless device. The apparatus further includes atransmitter configured to transmit a probe response including sharedaccess point state information. The receiver is further configured toreceive an association request including an indication that the wirelessdevice has stored the shared access point state information. Thetransmitter is further configured to transmit an association responseomitting the shared access point state information.

Another aspect of the present disclosure provides an apparatusconfigured to communicate in a high-efficiency wireless communicationnetwork. The apparatus includes a transmitter configured to transmit aprobe request to an access point. The apparatus further includes areceiver configured to receive a probe response including shared accesspoint state information. The apparatus further includes a memoryconfigured to store the shared access point state information. Thetransmitter is further configured to transmit an association requestincluding an indication that the wireless device has stored the sharedaccess point state information. The receiver is further configured toreceive an association response omitting the shared access point stateinformation.

Another aspect of the present disclosure provides a non-transitorycomputer-readable medium. The medium includes code that, when executed,causes an apparatus to receive a probe request including a transmissionpower indication. The medium further includes code that, when executed,causes the apparatus to determine a received transmission power. Themedium further includes code that, when executed, causes the apparatusto estimate a path-loss based on the transmission power indication andreceived transmission power. The medium further includes code that, whenexecuted, causes the apparatus to transmit a first probe response at afirst rate. The medium further includes code that, when executed, causesthe apparatus to transmit a second probe response at a second rate whenthe access point does not receive an acknowledgement to the first proberesponse within a timeout period, the second rate being lower than thefirst rate.

Another aspect of the present disclosure provides a non-transitorycomputer-readable medium. The medium includes code that, when executed,causes an apparatus to transmit a probe request including a transmissionpower indication. The medium further includes code that, when executed,causes the apparatus to receive, from an access point, a probe responseat either a first or second rate, the second rate being lower than thefirst rate. The medium further includes code that, when executed, causesthe apparatus to transmit an acknowledgement to the probe response ateither the first or second rate based on the rate of the probe response.

Another aspect of the present disclosure provides a non-transitorycomputer-readable medium. The medium includes code that, when executed,causes an apparatus to transmit one or more frames each including atransmission power indication. The medium further includes code that,when executed, causes the apparatus to receive a probe request at afirst rate. The medium further includes code that, when executed, causesthe apparatus to transmit a probe response at a second rate, the secondrate being a function of the first rate.

Another aspect of the present disclosure provides a non-transitorycomputer-readable medium. The medium includes code that, when executed,causes an apparatus to receive one or more frames from an access point,each frame including a transmission power indication. The medium furtherincludes code that, when executed, causes the apparatus to estimate alink quality based on the transmission power indication. The mediumfurther includes code that, when executed, causes the apparatus totransmit a probe request at a first rate compatible with the estimatedlink quality. The medium further includes code that, when executed,causes the apparatus to receive a probe response at a second rate, thesecond rate being a function of the first rate.

Another aspect of the present disclosure provides a non-transitorycomputer-readable medium. The medium includes code that, when executed,causes an apparatus to receive a probe request. The medium furtherincludes code that, when executed, causes the apparatus to generating aprobe response in response to the probe request. The medium furtherincludes code that, when executed, causes the apparatus to conditionallyincluding neighbor report information in the probe response based on anindication or absence of an indication in the probe request. The mediumfurther includes code that, when executed, causes the apparatus totransmit the probe response to a wireless device.

Another aspect of the present disclosure provides a non-transitorycomputer-readable medium. The medium includes code that, when executed,causes an apparatus to determine whether neighborhood report informationis stored. The medium further includes code that, when executed, causesthe apparatus to transmit a probe request conditionally including arequest for neighbor report information based on said determine. Themedium further includes code that, when executed, causes the apparatusto receive a probe response. The probe response includes the neighborreport information when the probe request includes the request forneighbor report information.

Another aspect of the present disclosure provides a non-transitorycomputer-readable medium. The medium includes code that, when executed,causes an apparatus to receive a probe request including shared wirelessdevice state information. The medium further includes code that, whenexecuted, causes the apparatus to store the shared wireless device stateinformation for at least a timeout period. The medium further includescode that, when executed, causes the apparatus to transmit a proberesponse indicating the timeout period. The medium further includes codethat, when executed, causes the apparatus to receive an associationrequest omitting the wireless device state information within thetimeout period.

Another aspect of the present disclosure provides a non-transitorycomputer-readable medium. The medium includes code that, when executed,causes an apparatus to transmit a probe request including sharedwireless device state information. The medium further includes codethat, when executed, causes the apparatus to receive a probe responseindicating a timeout period. The medium further includes code that, whenexecuted, causes the apparatus to transmit an association requestomitting the wireless device state information within the timeoutperiod.

Another aspect of the present disclosure provides a non-transitorycomputer-readable medium. The medium includes code that, when executed,causes an apparatus to receive a probe request from a wireless device.The medium further includes code that, when executed, causes theapparatus to transmit a probe response including shared access pointstate information. The medium further includes code that, when executed,causes the apparatus to receive an association request including anindication that the wireless device has stored the shared access pointstate information. The medium further includes code that, when executed,causes the apparatus to transmit an association response omitting theshared access point state information.

Another aspect of the present disclosure provides a non-transitorycomputer-readable medium. The medium includes code that, when executed,causes an apparatus to transmit a probe request to an access point. Themedium further includes code that, when executed, causes the apparatusto receive a probe response including shared access point stateinformation. The medium further includes code that, when executed,causes the apparatus to store the shared access point state information.The medium further includes code that, when executed, causes theapparatus to transmit an association request including an indicationthat the wireless device has stored the shared access point stateinformation. The medium further includes code that, when executed,causes the apparatus to receive an association response omitting theshared access point state information.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an exemplary wireless communication system in which aspectsof the present disclosure may be employed.

FIG. 2 shows a functional block diagram of an exemplary wireless devicethat may be employed within the wireless communication systems of FIG.1.

FIG. 3 shows an embodiment of the wireless communication system in whichaspects of the present disclosure may be employed.

FIG. 4 shows a flowchart for an exemplary method of wirelesscommunication that can be employed within the wireless communicationsystem of FIG. 3.

FIG. 5 shows a flowchart for an exemplary method of wirelesscommunication that can be employed within the wireless communicationsystem of FIG. 3.

FIG. 6 shows an embodiment of the wireless communication system in whichaspects of the present disclosure may be employed.

FIG. 7 shows a flowchart for an exemplary method of wirelesscommunication that can be employed within the wireless communicationsystem of FIG. 6.

FIG. 8 shows a flowchart for an exemplary method of wirelesscommunication that can be employed within the wireless communicationsystem of FIG. 6.

FIG. 9 shows an embodiment of the wireless communication system in whichaspects of the present disclosure may be employed.

FIG. 10 shows a flowchart for an exemplary method of wirelesscommunication that can be employed within the wireless communicationsystem of FIG. 9.

FIG. 11 shows a flowchart for an exemplary method of wirelesscommunication that can be employed within the wireless communicationsystem of FIG. 9.

FIG. 12 shows an embodiment of the wireless communication system inwhich aspects of the present disclosure may be employed.

FIG. 13 shows a flowchart for an exemplary method of wirelesscommunication that can be employed within the wireless communicationsystem of FIG. 12.

FIG. 14 shows a flowchart for an exemplary method of wirelesscommunication that can be employed within the wireless communicationsystem of FIG. 12.

FIG. 15 shows an embodiment of the wireless communication system inwhich aspects of the present disclosure may be employed.

FIG. 16 shows a flowchart for an exemplary method of wirelesscommunication that can be employed within the wireless communicationsystem of FIG. 15.

FIG. 17 shows a flowchart for an exemplary method of wirelesscommunication that can be employed within the wireless communicationsystem of FIG. 15.

DETAILED DESCRIPTION

Various aspects of the novel systems, apparatuses, and methods aredescribed more fully hereinafter with reference to the accompanyingdrawings. This disclosure may, however, be embodied in many differentforms and should not be construed as limited to any specific structureor function presented throughout this disclosure. Rather, these aspectsare provided so that this disclosure will be thorough and complete, andwill fully convey the scope of the disclosure to those skilled in theart. Based on the teachings herein one skilled in the art shouldappreciate that the scope of the disclosure is intended to cover anyaspect of the novel systems, apparatuses, and methods disclosed herein,whether implemented independently of, or combined with, any other aspectof the invention. For example, an apparatus may be implemented or amethod may be practiced using any number of the aspects set forthherein. In addition, the scope of the invention is intended to coversuch an apparatus or method which is practiced using other structure,functionality, or structure and functionality in addition to or otherthan the various aspects of the invention set forth herein. It should beunderstood that any aspect disclosed herein may be embodied by one ormore elements of a claim.

Although particular aspects are described herein, many variations andpermutations of these aspects fall within the scope of the disclosure.Although some benefits and advantages of the preferred aspects arementioned, the scope of the disclosure is not intended to be limited toparticular benefits, uses, or objectives. Rather, aspects of thedisclosure are intended to be broadly applicable to different wirelesstechnologies, system configurations, networks, and transmissionprotocols, some of which are illustrated by way of example in thefigures and in the following description of the preferred aspects. Thedetailed description and drawings are merely illustrative of thedisclosure rather than limiting, the scope of the disclosure beingdefined by the appended claims and equivalents thereof.

Popular wireless network technologies may include various types ofwireless local area networks (WLANs). A WLAN may be used to interconnectnearby devices together, employing widely used networking protocols. Thevarious aspects described herein may apply to any communicationstandard, such as a wireless protocol.

In some aspects, wireless signals may be transmitted according to ahigh-efficiency 802.11 protocol using orthogonal frequency-divisionmultiplexing (OFDM), direct-sequence spread spectrum (DSSS)communications, a combination of OFDM and DSSS communications, or otherschemes. Implementations of the high-efficiency 802.11 protocol may beused for Internet access, sensors, metering, smart grid networks, orother wireless applications. Advantageously, aspects of certain devicesimplementing the high-efficiency 802.11 protocol using the techniquesdisclosed herein may include allowing for increased peer-to-peerservices (e.g., Miracast, WiFi Direct Services, Social WiFi, etc.) inthe same area, supporting increased per-user minimum throughputrequirements, supporting more users, providing improved outdoor coverageand robustness, and/or consuming less power than devices implementingother wireless protocols.

In some implementations, a WLAN includes various devices which are thecomponents that access the wireless network. For example, there may betwo types of devices: access points (“APs”) and clients (also referredto as stations, or “STAs”). In general, an access point may serve as ahub or base station for the WLAN and an wireless device serves as a userof the WLAN. For example, an wireless device may be a laptop computer, apersonal digital assistant (PDA), a mobile phone, etc. In an example, anwireless device connects to an access point via a WiFi (e.g., IEEE802.11 protocol) compliant wireless link to obtain general connectivityto the Internet or to other wide area networks. In some implementationsan wireless device may also be used as an access point.

An access point (“AP”) may also comprise, be implemented as, or known asa NodeB, Radio Network Controller (“RNC”), eNodeB, Base StationController (“BSC”), Base Transceiver Station (“BTS”), Base Station(“BS”), Transceiver Function (“TF”), Radio Router, Radio Transceiver, orsome other terminology.

A station “STA” may also comprise, be implemented as, or known as anaccess terminal (“AT”), a subscriber station, a subscriber unit, amobile station, a remote station, a remote terminal, a user terminal, auser agent, a user device, user equipment, or some other terminology. Insome implementations an access terminal may comprise a cellulartelephone, a cordless telephone, a Session Initiation Protocol (“SIP”)phone, a wireless local loop (“WLL”) station, a personal digitalassistant (“PDA”), a handheld device having wireless connectioncapability, or some other suitable processing device connected to awireless modem. Accordingly, one or more aspects taught herein may beincorporated into a phone (e.g., a cellular phone or smartphone), acomputer (e.g., a laptop), a portable communication device, a headset, aportable computing device (e.g., a personal data assistant), anentertainment device (e.g., a music or video device, or a satelliteradio), a gaming device or system, a global positioning system device,or any other suitable device that is configured to communicate via awireless medium.

As discussed above, in various embodiments, a large amount of channeltime can be consumed by beacons and probe responses. This can beparticularly true in dense networks. In one embodiment disclosed here,channel time can be reduced by transmitting frames such as proberesponses at a high rate. In some embodiments, the rate at which theprobe responses are sent can be selected via a rate function describedherein. In a third embodiment, channel time can be reduced by omittingneighbor information in frames such as beacons and probe responsesunless requested by a station. A fourth embodiment reduces channel timeby omitting at least some data shared between probe requests andassociation requests. In a fifth embodiment, channel time may be reducedby omitting at least some data shared between probe responses andassociation responses. The reduced channel time provided by theembodiment disclosed herein can result in increased overall networkefficiency.

FIG. 1 shows an exemplary wireless communication system 100 in whichaspects of the present disclosure may be employed. The wirelesscommunication system 100 may operate pursuant to a wireless standard,for example a high-efficiency 802.11 standard. The wirelesscommunication system 100 may include an access point 104, whichcommunicates with wireless devices 106.

A variety of processes and methods may be used for transmissions in thewireless communication system 100 between the access point 104 and thewireless devices 106. For example, signals may be sent and receivedbetween the access point 104 and the wireless devices 106 in accordancewith OFDM/OFDMA techniques. If this is the case, the wirelesscommunication system 100 may be referred to as an OFDM/OFDMA system.Alternatively, signals may be sent and received between the access point104 and the wireless devices 106 in accordance with code divisionmultiple access (CDMA) techniques. If this is the case, the wirelesscommunication system 100 may be referred to as a CDMA system.

A communication link that facilitates transmission from the access point104 to one or more of the wireless devices 106 may be referred to as adownlink (DL) 108, and a communication link that facilitatestransmission from one or more of the wireless devices 106 to the accesspoint 104 may be referred to as an uplink (UL) 110. Alternatively, adownlink 108 may be referred to as a forward link or a forward channel,and an uplink 110 may be referred to as a reverse link or a reversechannel.

The access point 104 may act as a base station and provide wirelesscommunication coverage in a basic service area (BSA) 102. The accesspoint 104 along with the wireless devices 106 associated with the accesspoint 104 and that use the access point 104 for communication may bereferred to as a basic service set (BSS). It should be noted that thewireless communication system 100 may not have a central access point104, but rather may function as a peer-to-peer network between thewireless devices 106. Accordingly, the functions of the access point 104described herein may alternatively be performed by one or more of thewireless devices 106.

In some aspects, a wireless device 106 may be required to associate withthe access point 104 in order to send communications to and/or receivecommunications from the access point 104. In one aspect, information forassociating is included in a broadcast by the access point 104. Toreceive such a broadcast, the wireless device 106 may, for example,perform a broad coverage search over a coverage region. A search mayalso be performed by the wireless device 106 by sweeping a coverageregion in a lighthouse fashion, for example. After receiving theinformation for associating, the wireless device 106 may transmit areference signal, such as an association probe or request, to the accesspoint 104. In some aspects, the access point 104 may use backhaulservices, for example, to communicate with a larger network, such as theInternet or a public switched telephone network (PSTN).

FIG. 2 shows an exemplary functional block diagram of a wireless device402 that may be employed within the wireless communication systems 100of FIG. 1. The wireless device 402 is an example of a device that may beconfigured to implement the various methods described herein. Forexample, the wireless device 402 may comprise the access point 104, oneof the wireless devices 106.

The wireless device 402 may include a processor 404 which controlsoperation of the wireless device 402. The processor 404 may also bereferred to as a central processing unit (CPU). Memory 406, which mayinclude both read-only memory (ROM) and random access memory (RAM), mayprovide instructions and data to the processor 404. A portion of thememory 406 may also include non-volatile random access memory (NVRAM).The processor 404 typically performs logical and arithmetic operationsbased on program instructions stored within the memory 406. Theinstructions in the memory 406 may be executable to implement themethods described herein.

The processor 404 may comprise or be a component of a processing systemimplemented with one or more processors. The one or more processors maybe implemented with any combination of general-purpose microprocessors,microcontrollers, digital signal processors (DSPs), field programmablegate array (FPGAs), programmable logic devices (PLDs), controllers,state machines, gated logic, discrete hardware components, dedicatedhardware finite state machines, or any other suitable entities that canperform calculations or other manipulations of information.

The processing system may also include machine-readable media forstoring software. Software shall be construed broadly to mean any typeof instructions, whether referred to as software, firmware, middleware,microcode, hardware description language, or otherwise. Instructions mayinclude code (e.g., in source code format, binary code format,executable code format, or any other suitable format of code). Theinstructions, when executed by the one or more processors, cause theprocessing system to perform the various functions described herein.

The wireless device 402 may also include a housing 408 that may includea transmitter 410 and/or a receiver 412 to allow transmission andreception of data between the wireless device 402 and a remote location.The transmitter 410 and receiver 412 may be combined into a transceiver414. An antenna 416 may be attached to the housing 408 and electricallycoupled to the transceiver 414. The wireless device 402 may also include(not shown) multiple transmitters, multiple receivers, multipletransceivers, and/or multiple antennas.

The wireless device 402 may also include a signal detector 418 that maybe used in an effort to detect and quantify the level of signalsreceived by the transceiver 414. The signal detector 418 may detect suchsignals as total energy, energy per subcarrier per symbol, powerspectral density and other signals. The wireless device 402 may alsoinclude a digital signal processor (DSP) 420 for use in processingsignals. The DSP 420 may be configured to generate a packet fortransmission. In some aspects, the packet may comprise a physical layerdata unit (PPDU).

The wireless device 402 may further comprise a user interface 422 insome aspects. The user interface 422 may comprise a keypad, amicrophone, a speaker, and/or a display. The user interface 422 mayinclude any element or component that conveys information to a user ofthe wireless device 402 and/or receives input from the user.

The various components of the wireless device 402 may be coupledtogether by a bus system 426. The bus system 426 may include a data bus,for example, as well as a power bus, a control signal bus, and a statussignal bus in addition to the data bus. Those of skill in the art willappreciate the components of the wireless device 402 may be coupledtogether or accept or provide inputs to each other using some othermechanism.

Although a number of separate components are illustrated in FIG. 2,those of skill in the art will recognize that one or more of thecomponents may be combined or commonly implemented. For example, theprocessor 404 may be used to implement not only the functionalitydescribed above with respect to the processor 404, but also to implementthe functionality described above with respect to the signal detector418 and/or the DSP 420. Further, each of the components illustrated inFIG. 2 may be implemented using a plurality of separate elements.

The wireless device 402 may comprise an access point 104, a wirelessdevice 106, an access point 254, a wireless device 256, and/or an accesspoint 304, and may be used to transmit and/or receive communications.That is, either the access point 104, wireless device 106, access point254, wireless device 256, or access point 304 may serve as transmitteror receiver devices. Certain aspects contemplate signal detector 418being used by software running on memory 406 and processor 404 to detectthe presence of a transmitter or receiver.

Rate Selection Via Acknowledgement

As discussed above, in various embodiments, a large amount of channeltime can be consumed by beacons and probe responses. This can beparticularly true in dense networks. In one embodiment, channel time canbe reduced by transmitting frames such as probe responses at a highrate. In some embodiments, a highest functioning modulation and codingscheme (MCS) can be determined. Reduced channel time can increaseoverall network efficiency. In some embodiments, the rate can beselected via probe response and acknowledgement system described herein.

FIG. 3 shows an embodiment of the wireless communication system 500 inwhich aspects of the present disclosure may be employed. As shown, thewireless communication system 500 includes the access point 104 and awireless device 106. The wireless communication system 500 can besimilar to the wireless communication system 100, described above withrespect to FIG. 1. For example, the access point 104 can include theaccess point 104 shown in FIG. 1, and the wireless device 106 caninclude any of the wireless devices 106 a-106 d shown in FIG. 1. Invarious embodiments, the access point 104 and/or the wireless device 106can include the wireless device 402 (FIG. 2) or any other suitabledevice.

FIG. 3 illustrates an exemplary communication exchange between theaccess point 104 and the wireless device 106. In the illustratedcommunication exchange, the access point 104 is configured to determinea communication rate. For example, the access point 104 can beconfigured to determine a highest effective MCS. Although theillustrated communications are shown and described herein with referenceto a particular order, in various embodiments, communication herein canbe performed in a different order, or omitted, and additionalcommunications can be added.

First, the wireless device 106 transmits a probe request 510. The proberequest 510 includes a transmission power indication. In someembodiments, the probe request 510 further includes one or moreadditional indications of the wireless device's 106 capabilities. Forexample, the probe request 510 can include a number of transmit and/orreceive antennas on the wireless device 106.

The access point 104 can determine a received transmission power basedon the probe request 510. The access point 104 can further estimate apath-loss based on one or more of the transmission power indication, thereceived transmission power, and the indications of the wirelessdevice's 106 capabilities. The access point 104 can determine a firstset of communication parameters based on the probe request and thereceived power indication. The communication parameters may control howa particular transmission occurs between the access point and adestination device. For example, the access point 104 can determine afirst data rate or MCS at which to transmit a probe response. The firstdata rate or MCS can be based on the estimated path-loss.

Then, the access point 104 transmits a first probe response 520 using orbased on a first set of communication parameters defining a first datarate or MCS. In some embodiments, the first data rate or MCS is notcompatible with network characteristics and the wireless device 106 doesnot receive the first probe response 520. In other embodiments, thefirst data rate or MCS is compatible with network characteristics andthe wireless device 106 can receive the first probe response 520 (notshown).

The access point 104 can wait for a timeout period for the wirelessdevice 106 to acknowledge the first probe response 520. In embodimentswhere the wireless device 106 receives the first probe response 520, thewireless device 106 can acknowledge the first probe response 520 usingthe first set of communication parameters within the timeout period. Inembodiments where in embodiments where the wireless device 106 does notacknowledge the first probe response 520 within the timeout period, theaccess point 104 can select a second set of communication parameters,defining a second data rate or MCS.

Next, the access point 104 can transmit a second probe response 530using the second set of communication parameters. In variousembodiments, the second data rate defined by the second set ofcommunication parameters can be lower than the first data rate. In someembodiments, the second data rate can be a next lowest available rate orMCS after the first data rate. In the illustrated embodiment, thewireless device 106 receives the second probe response 530. In otherembodiments where the wireless device 106 does not receive oracknowledge probe responses, the access point 104 can continue to sendsuccessive probe responses using third, fourth, and fifth sets ofcommunication parameters, each defining successively lower rates orMCSs, for example up to a threshold number of responses.

Thereafter, the wireless device 106 acknowledges the second proberesponse 530. The wireless device 106 can acknowledge the second proberesponse 530 using a media access control (MAC)-level acknowledgement.In various embodiments, the wireless device 106 can use the second setof communication parameters for the acknowledgement and/or successivecommunications with the access point 104. Likewise, the access point 104can continue to use the second set of communication parameters forsuccessive communications with the wireless device 106.

FIG. 4 shows a flowchart 600 for an exemplary method of wirelesscommunication that can be employed within the wireless communicationsystem 500 of FIG. 5. The method can be implemented in whole or in partby the devices described herein, such as the wireless device 402 shownin FIG. 2. Although the illustrated method is described herein withreference to the wireless communication system 60 discussed above withrespect to FIG. 1, the wireless communication systems 500 discussedabove with respect to FIG. 3, and the wireless device 402 discussedabove with respect to FIG. 2, a person having ordinary skill in the artwill appreciate that the illustrated method can be implemented byanother device described herein, or any other suitable device. Althoughthe illustrated method is described herein with reference to aparticular order, in various embodiments, blocks herein can be performedin a different order, or omitted, and additional blocks can be added.

Method 600 may be used by one of two communicating wireless devices. Themethod 600 may provide for one of the devices to determine communicationparameters for transmission between the two devices that improveutilization of the wireless medium compared to known methods. Forexample, use of the method 600 may allow a device to determine a set ofcommunication parameters used to transmit a probe response that improvenetwork utilization of the transmission of the probe response. Thisdetermined set of communication parameters may then be applied to othertypes of frames as well, resulting in a further improvement to networkutilization.

First, at block 610, an access point receives a probe request includinga transmission power indication. For example, the access point 104 canreceive the probe request 510 from the wireless device 106. The proberequest may be decoded by the access point to determine the transmissionpower indication. In various embodiments, the probe request can furtherinclude one or more receive capability indications such as, for example,a number of antennas of the wireless device 106. The access point mayfurther decode the probe request to determine one or more of theincluded receive capability indications.

Then, at block 620, the access point determines a received transmissionpower. For example, the access point 104 can determine a receivedtransmission power for the probe request 510.

Next, at block 630, the access point estimates a path-loss based on thetransmission power indication and received transmission power. Forexample, the access point 104 can determine a path-loss to the wirelessdevice 106 based on the probe request 510. In some embodiments, theaccess point can estimate the path-loss further based on the one or morereceive capability indications, such as the number of antennas of thewireless device 10 in some aspects.

Then, at block 640, the access point transmits a first probe responseusing or based on a first set of communication parameters defining afirst data rate. For example, the access point 104 can transmit thefirst probe response 520 to the wireless device 106 at the first datarate based on the estimated path loss. In some aspects, the first set ofcommunication parameters define a first modulation coding scheme (MCS).

Subsequently, at block 650, the access point transmits a second proberesponse using or based on a second set of communication parametersdefining a second data rate when the access point does not receive anacknowledgement to the first probe response within a timeout period. Insome aspects, the acknowledgment message that the access point iswaiting for is a media access control (MAC) level acknowledgment.

The second data rate is lower than the first data rate. For example, theaccess point 104 can transmit the second probe response 530 to thewireless device 106 at the second data rate. In an embodiment, thesecond data rate can be a next lowest MCS from the first data rate.

As discussed above, in various embodiments, the access point cancontinue to retransmit probe responses using third, fourth, or fifthsets of communication parameters, each set of communication parametersdefining successively lower rates, for example up to a maximum number ofretransmissions until an acknowledgment is received. If and when thewireless device 106 acknowledges a probe response, the access point 104and/or the wireless device 106 can select the set of communicationparameters that resulted in successful acknowledgment for furthercommunication. For example in some aspects, the rate used to transmitthe acknowledged probe response may be selected for furthercommunication with the device.

In an embodiment, the method shown in FIG. 4 can be implemented in awireless device that can include a receiving circuit, a determiningcircuit, an estimating circuit, and a transmitting circuit. Thoseskilled in the art will appreciate that a wireless device can have morecomponents than the simplified wireless device described herein. Thewireless device described herein includes only those components usefulfor describing some prominent features of implementations within thescope of the claims.

The receiving circuit can be configured to receive the probe request. Insome embodiments, the receiving circuit can be configured to perform atleast block 610 of FIG. 4. The receiving circuit can include one or moreof the processor 404 (FIG. 2), the receiver 412 (FIG. 2), the antenna416 (FIG. 2), and the transceiver 414 (FIG. 2). In some implementations,means for receiving can include the receiving circuit.

The determining circuit can be configured to determine the receivedtransmission power. In some embodiments, the determining circuit can beconfigured to perform at least block 620 of FIG. 4. The determiningcircuit can include one or more of the processor 404 (FIG. 2), the DSP420, the signal detector 418 (FIG. 2), the receiver 412 (FIG. 2), andthe memory 406 (FIG. 2). In some implementations, means for determiningcan include the determining circuit.

The estimating circuit can be configured to estimate the path-loss. Insome embodiments, the estimating circuit can be configured to perform atleast block 630 of FIG. 4. The estimating circuit can include one ormore of the processor 404 (FIG. 2), the DSP 420, the signal detector 418(FIG. 2), the receiver 412 (FIG. 2), and the memory 406 (FIG. 2). Insome implementations, means for estimating can include the estimatingcircuit.

The transmitting circuit can be configured to transmit the proberesponses. In some embodiments, the transmitting circuit can beconfigured to perform at least blocks 640 and/or 650 of FIG. 4. Thetransmitting circuit can include one or more of the processor 404 (FIG.2), the transmitter 410 (FIG. 2), the antenna 416 (FIG. 2), and thetransceiver 414 (FIG. 2). In some implementations, means fortransmitting can include the transmitting circuit.

Method 700 may be used by one of two communicating wireless devices. Themethod 700 may provide for one of the devices to determine communicationparameters for transmission between the two devices that improveutilization of the wireless medium compared to known methods. Forexample, use of the method 700 may allow a device to determine a set ofcommunication parameters used to transmit a probe response that improvenetwork utilization of the transmission of the probe response. Thisdetermined set of communication parameters may then be applied to othertypes of frames as well, resulting in a further improvement to networkutilization.

FIG. 5 shows a flowchart 700 for an exemplary method of wirelesscommunication that can be employed within the wireless communicationsystem 500 of FIG. 3. The method can be implemented in whole or in partby the devices described herein, such as the wireless device 402 shownin FIG. 2. Although the illustrated method is described herein withreference to the wireless communication system 70 discussed above withrespect to FIG. 1, the wireless communication systems 500 discussedabove with respect to FIG. 3, and the wireless device 402 discussedabove with respect to FIG. 2, a person having ordinary skill in the artwill appreciate that the illustrated method can be implemented byanother device described herein, or any other suitable device. Althoughthe illustrated method is described herein with reference to aparticular order, in various embodiments, blocks herein can be performedin a different order, or omitted, and additional blocks can be added.

First, at block 710, a wireless device transmits a probe request. Theprobe request includes a transmission power indication. For example, thewireless device 106 can transmit the probe request 510 to the accesspoint 104. In some embodiments, the probe request can include one ormore receive capabilities of the wireless device. For example, the proberequest may include a receive capability indicating the number ofantennas present on the wireless device.

Then, at block 720, the wireless device receives a probe response usingeither a first set of communication parameters defining a first datarate or a second set of communication parameters defining a second datarate. For example, the wireless device 106 can receive either the firstprobe response 520 or the second probe response 530 from the accesspoint 104. The first and/or second sets of communication parameters candefine an MCS.

Subsequently, at block 730, the wireless device transmits anacknowledgement to the probe response using either the first or secondset of communication parameters based on the communication parametersused to receive the probe response. In some aspects, the transmittedacknowledgment is a media access control (MAC) level acknowledgment.

In some aspects, the wireless device 106 can transmit theacknowledgement 540 to the access point 104 using the second set ofcommunication parameters when the wireless device 106 receives thesecond probe response 530 using the second set of communicationparameters. In embodiments where the wireless device 106 receives thefirst probe response 520 using the first set of communicationparameters, the wireless device 106 can transmit the acknowledgement tothe access point 104 using the first set of communication parameters.

In an embodiment, the method shown in FIG. 5 can be implemented in awireless device that can include a transmitting circuit and a receivingcircuit. Those skilled in the art will appreciate that a wireless devicecan have more components than the simplified wireless device describedherein. The wireless device described herein includes only thosecomponents useful for describing some prominent features ofimplementations within the scope of the claims.

The transmitting circuit can be configured to transmit the probe requestand/or acknowledgement. In some embodiments, the transmitting circuitcan be configured to perform at least blocks 710 and/or 730 of FIG. 5.The transmitting circuit can include one or more of the processor 404(FIG. 2), the transmitter 410 (FIG. 2), the antenna 416 (FIG. 2), andthe transceiver 414 (FIG. 2). In some implementations, means fortransmitting can include the transmitting circuit.

The receiving circuit can be configured to receive the probe response.In some embodiments, the receiving circuit can be configured to performat least block 720 of FIG. 5. The receiving circuit can include one ormore of the processor 404 (FIG. 2), the receiver 412 (FIG. 2), theantenna 416 (FIG. 2), and the transceiver 414 (FIG. 2). In someimplementations, means for receiving can include the receiving circuit.

Rate Selection Via Function

As discussed above, in various embodiments, a large amount of channeltime can be consumed by beacons and probe responses. This can beparticularly true in dense networks. In one embodiment, channel time canbe reduced by transmitting frames such as probe responses at a highrate. In some embodiments, a highest functioning modulation and codingscheme (MCS) can be determined. Reduced channel time can increaseoverall network efficiency. In some embodiments, the rate can beselected via probe request and response function described herein.

FIG. 6 shows an embodiment of the wireless communication system 800 inwhich aspects of the present disclosure may be employed. As shown, thewireless communication system 800 includes the access point 104 and awireless device 106. The wireless communication system 800 can besimilar to the wireless communication system 100, described above withrespect to FIG. 1. For example, the access point 104 can include theaccess point 104 shown in FIG. 1, and the wireless device 106 caninclude any of the wireless devices 106 a-106 d shown in FIG. 1. Invarious embodiments, the access point 104 and/or the wireless device 106can include the wireless device 402 (FIG. 2) or any other suitabledevice.

FIG. 6 illustrates an exemplary communication exchange between theaccess point 104 and the wireless device 106. In the illustratedcommunication exchange, the access point 104 is configured to determinea communication rate. For example, the access point 104 can beconfigured to determine a highest effective MCS. Although theillustrated communications are shown and described herein with referenceto a particular order, in various embodiments, communication herein canbe performed in a different order, or omitted, and additionalcommunications can be added.

First, the access point 104 transmits one or more frames 810 eachincluding a transmission power indication. In some embodiments, one ormore frames 810 can each further include one or more additionalindications of the access point 104 capabilities. For example, theframes 810 can include a number of transmit and/or receive antennas onthe access point 104.

The wireless device 106 can determine a received transmission powerbased on the frames 810. The wireless device 106 can further estimate apath-loss based on one or more of the transmission power indication, thereceived transmission power, and the indications of the Aps 104capabilities. The wireless device 106 can determine a first set ofcommunication parameters at which to transmit the probe request. Forexample, the wireless device 106 can determine a first coding rate orMCS at which to transmit a probe request. The first data rate or MCS canbe based on the estimated path-loss. Then, the wireless device 106transmits a probe request 820 using the first set of communicationparameters.

Next, the access point 104 can transmit a probe response 830 using orbased on a second set of communication parameters. For example, theprobe response 830 may be transmitted at a second coding rate or MCS. Invarious embodiments, the second set of communication parameters can be afunction of the first set of communication parameters. For example, thesecond set of communication parameters can be a direct mapping of thesecond set of communication parameters to the first set of communicationparameters. In some embodiments, the function can indicate that a seconddata rate of the second set of communication parameters may be less thanor equal to a first data rate defined by the first set of communicationparameters. In some embodiments, the function can include additionalfactors such as one or more of: a transmit power indication, a transmitpower measurement, a receive power indication, and a receive powermeasurement. In some embodiments, the second set of communicationparameters can be equal to the first set of communication parameters forcertain communication parameters.

FIG. 7 shows a flowchart 900 for an exemplary method of wirelesscommunication that can be employed within the wireless communicationsystem 800 of FIG. 6. The method can be implemented in whole or in partby the devices described herein, such as the wireless device 402 shownin FIG. 2. Although the illustrated method is described herein withreference to the wireless communication system 100 discussed above withrespect to FIG. 1, the wireless communication systems 800 discussedabove with respect to FIG. 6, and the wireless device 402 discussedabove with respect to FIG. 2, a person having ordinary skill in the artwill appreciate that the illustrated method can be implemented byanother device described herein, or any other suitable device. Althoughthe illustrated method is described herein with reference to aparticular order, in various embodiments, blocks herein can be performedin a different order, or omitted, and additional blocks can be added.

In some aspects, the method 900 is used by one of two communicatingdevices to jointly determine communication parameters appropriate forthe quality of the link between the two devices. This may provide forincreased transmission speeds and therefore more efficient utilizationof a wireless medium bandwidth in some aspects. For example, by someaspects determining an MCS based on a plurality of frames transmittedfrom one device to another, an MCS used to exchange probe requests andresponses between the two devices may be increased relate to a MCS thatmay be used in known methods. As probe traffic can comprise asignificant percentage of wireless traffic on some networks, increasingthe MCS used to transmit probe messages may improve utilization of thewireless medium when compared to known methods.

First, at block 910, the access point transmits one or more frames. Eachframe includes a transmission power indication. The frames can include,for example, beacons, short beacons, broadcast frames, probe responses,etc. For example, the access point 104 can transmit one or more beaconframes to the wireless device 106.

Next, at block 920, the access point receives a probe request using orbased on a first set of communication parameters. The first set ofcommunication parameters may control how the receive process of block920 is performed. For example, the first set of communication parametersmay define an MCS used to receive the probe request. The MCS may definea coding rate used to receive the probe request. The access point 104can receive the probe request 820 from the wireless device 106. In someembodiments, the access point 104 can determine a second set ofcommunication parameters based on the first set of communicationparameters, for example according to a function as discussed above.

Then, at block 930, the access point transmits a probe response using orbased on a second set of communication parameters. For example, theaccess point 104 can transmit the probe response 830 to the wirelessdevice 106. In various embodiments, the access point 104 can continue touse the second set of communication parameters for future communicationswith the wireless device 106.

In an embodiment, the method shown in FIG. 7 can be implemented in awireless device that can include a transmitting circuit and a receivingcircuit. Those skilled in the art will appreciate that a wireless devicecan have more components than the simplified wireless device describedherein. The wireless device described herein includes only thosecomponents useful for describing some prominent features ofimplementations within the scope of the claims.

The transmitting circuit can be configured to transmit the one or moreframes. In some embodiments, the transmitting circuit can be configuredto perform at least blocks 910 and/or 930 of FIG. 7. The transmittingcircuit can include one or more of the processor 404 (FIG. 2), thetransmitter 410 (FIG. 2), the antenna 416 (FIG. 2), and the transceiver414 (FIG. 2). In some implementations, means for transmitting caninclude the transmitting circuit.

The receiving circuit can be configured to receive the probe request. Insome embodiments, the receiving circuit can be configured to perform atleast block 920 of FIG. 7. The receiving circuit can include one or moreof the processor 404 (FIG. 2), the receiver 412 (FIG. 2), the antenna416 (FIG. 2), and the transceiver 414 (FIG. 2). In some implementations,means for receiving can include the receiving circuit.

FIG. 8 shows a flowchart 1000 for an exemplary method of wirelesscommunication that can be employed within the wireless communicationsystem 800 of FIG. 6. The method can be implemented in whole or in partby the devices described herein, such as the wireless device 402 shownin FIG. 2. Although the illustrated method is described herein withreference to the wireless communication system 100 discussed above withrespect to FIG. 1, the wireless communication systems 800 discussedabove with respect to FIG. 6, and the wireless device 402 discussedabove with respect to FIG. 2, a person having ordinary skill in the artwill appreciate that the illustrated method can be implemented byanother device described herein, or any other suitable device. Althoughthe illustrated method is described herein with reference to aparticular order, in various embodiments, blocks herein can be performedin a different order, or omitted, and additional blocks can be added.

In some aspects, the method 1000 is used by one of two communicatingdevices to jointly determine communication parameters appropriate forthe quality of the link between the two devices. This may provide forincreased transmission speeds and therefore more efficient utilizationof a wireless medium bandwidth in some aspects. For example, by someaspects determining an MCS based on a plurality of frames transmittedfrom one device to another, an MCS used to exchange probe requests andresponses between the two devices may be increased relate to a MCS thatmay be used in known methods. As probe traffic can comprise asignificant percentage of wireless traffic on some networks, increasingthe MCS used to transmit probe messages may improve utilization of thewireless medium when compared to known methods.

First, at block 1010, the wireless device receives one or more framesfrom an access point. Each frame may be decoded to determine atransmission power indication. For example, the wireless device 106 canreceive the frames 810 from the access point 104.

Next, at block 1020, the wireless device estimates a link quality basedon the one or more received transmission power indication(s). Forexample, the wireless device 106 can estimate a link quality to theaccess point 104 based on one or more of the transmission powerindication, a received power measurement, and/or receive capabilityinformation for the access point 104, etc.

Then, at block 1030, the wireless device transmits a probe request usingor based on a first set of communication parameters based on theestimated link quality. In some aspects, the first set of communicationparameters is determined such that they are compatible with theestimated link quality. For example, in some aspects, the wirelessdevice may maintain a mapping between one or more estimated linkqualities and communication parameters compatible with each linkquality. Generally, the higher the quality of the link, the highercoding rate that may be used, while still maintaining a low packet errorand/or loss rate.

In some aspects, the wireless device 106 may transmit the probe request820 to the access point 104. The probe request 820 can be transmittedusing the first set of communication parameters, such as a set defininga minimum coding rate. In some aspects, the minimum coding rate may beone of a plurality of rates determined to be compatible with theestimated link quality.

Thereafter, at block 1040, the wireless device receives a probe responseusing or based on a second set of communication parameters. The secondset of communication parameters is a function of the first set ofcommunication parameters, as described above. For example, the wirelessdevice 106 can receive the probe response 830 from the access point 104.

In an embodiment, the method shown in FIG. 8 can be implemented in awireless device that can include a receiving circuit, an estimatingcircuit, and a transmitting circuit. Those skilled in the art willappreciate that a wireless device can have more components than thesimplified wireless device described herein. The wireless devicedescribed herein includes only those components useful for describingsome prominent features of implementations within the scope of theclaims.

The receiving circuit can be configured to receive the one or moreframes and/or the probe response. In some embodiments, the receivingcircuit can be configured to perform at least blocks 1010 and/or 1040 ofFIG. 8. The receiving circuit can include one or more of the processor404 (FIG. 2), the receiver 412 (FIG. 2), the antenna 416 (FIG. 2), andthe transceiver 414 (FIG. 2). In some implementations, means forreceiving can include the receiving circuit.

The estimating circuit can be configured to estimate the link quality.In some embodiments, the estimating circuit can be configured to performat least block 1020 of FIG. 8. The estimating circuit can include one ormore of the processor 404 (FIG. 2), the DSP 420, the signal detector 418(FIG. 2), the receiver 412 (FIG. 2), and the memory 406 (FIG. 2). Insome implementations, means for estimating can include the estimatingcircuit.

The transmitting circuit can be configured to transmit the proberequest. In some embodiments, the transmitting circuit can be configuredto perform at least block 1020 of FIG. 8. The transmitting circuit caninclude one or more of the processor 404 (FIG. 2), the transmitter 410(FIG. 2), the antenna 416 (FIG. 2), and the transceiver 414 (FIG. 2). Insome implementations, means for transmitting can include thetransmitting circuit.

Beacon Size Reduction

As discussed above, in various embodiments, a large amount of channeltime can be consumed by beacons and probe responses. This can beparticularly true in dense networks. In one embodiment, channel time canbe reduced by omitting neighbor information in frames such as beaconsand probe responses unless requested by a station. The neighborinformation may include information gathered by a first access pointpertaining to one or more characteristics of other access points withina proximity of the first access point. For example, for each accesspoint identified within neighbor information, one or more of thefollowing may be included MAC address, security parameters associatedwith the access point, channel number, regulatory class, phy options,TBTT Offset, beacon interval parameters, reachability (not reachable,unknown, reachable).

Reduced channel time can increase overall network efficiency. In someembodiments, the access point can conditionally include neighbor reportinformation in a probe response, based on an indication in a proberequest.

FIG. 9 shows an embodiment of the wireless communication system 1100 inwhich aspects of the present disclosure may be employed. As shown, thewireless communication system 1100 includes the access point 104 and awireless device 106. The wireless communication system 1100 can besimilar to the wireless communication system 100, described above withrespect to FIG. 1. For example, the access point 104 can include theaccess point 104 shown in FIG. 1, and the wireless device 106 caninclude any of the wireless devices 106 a-106 d shown in FIG. 1. Invarious embodiments, the access point 104 and/or the wireless device 106can include the wireless device 402 (FIG. 2) or any other suitabledevice.

FIG. 9 illustrates an exemplary communication exchange between theaccess point 104 and the wireless device 106. In the illustratedcommunication exchange, the access point 104 can be configured toconditionally include neighbor report information in a probe response.Although the illustrated communications are shown and described hereinwith reference to a particular order, in various embodiments,communication herein can be performed in a different order, or omitted,and additional communications can be added.

First, the wireless device 106 receives a beacon 1110. The beacon 1110omits neighbor report information (which could otherwise be included ina conventional beacon). Because the wireless device 106 has not yetreceived the neighbor report information, the wireless device 106 cangenerate a probe request 1120 including a request for neighbor reportinformation.

Then, the wireless device 106 transmits the probe request 1120 to theaccess point 104. In some embodiments, probe request 1120 can include aninformation element (IE) indicating a request for neighbor reportinformation. In an embodiment, the IE can be referred to as a “NeighborReport Info Request.”

Thereafter, the access point 104 transmits a probe response 1130 to thewireless device 106. The probe response 1130 includes the requestedneighbor report information. The wireless device 106 can store theneighbor report information, for example in the memory 406 (FIG. 2).

In embodiments where the wireless device 106 has previously stored theneighbor report information, it can send a probe request 1140 omittingthe neighbor report information request. Thus, the access point 104 canrespond with a probe response 1150 omitting the neighbor reportinformation.

FIG. 10 shows a flowchart 1200 for an exemplary method of wirelesscommunication that can be employed within the wireless communicationsystem 1100 of FIG. 9. The method can be implemented in whole or in partby the devices described herein, such as the wireless device 402 shownin FIG. 2. Although the illustrated method is described herein withreference to the wireless communication system 120 discussed above withrespect to FIG. 1, the wireless communication systems 1100 discussedabove with respect to FIG. 9, and the wireless device 402 discussedabove with respect to FIG. 2, a person having ordinary skill in the artwill appreciate that the illustrated method can be implemented byanother device described herein, or any other suitable device. Althoughthe illustrated method is described herein with reference to aparticular order, in various embodiments, blocks herein can be performedin a different order, or omitted, and additional blocks can be added.

Method 1200 may be utilized by two devices communicating on a wirelessnetwork to reduce the amount of data transmitted between them. Forexample, known methods may transmit beacon frames that include neighborreport information. As beacon transmissions occur frequently, someportion of a wireless medium capacity may be consumed by thetransmission of neighbor report information. Many devices receiving theneighbor report information may already have received it from previousbeacon frames. Therefore, inclusion of the neighbor report informationis beacon frames may consume capacity of a wireless medium that may bebetter used for other purposes. Method 1200 provides a method to includeneighbor report information in a probe response message, and include theinformation in some aspects only when a device explicitly requests theinformation. This may reduce the total number of transmissions ofneighbor report information on a wireless network, thus freeing capacityof the wireless network for other uses.

First, at block 1210, the access point can receive a probe request. Forexample, the access point 104 can receive the probe request 1120 fromthe wireless device 106. The probe request 1120 can include anindication requesting neighbor report information. In some embodiments,the indication can explicitly request to send or not to send theneighbor report information. In other embodiments, the absence of anexplicit request can be interpreted as a request to send or not to sendthe neighbor report information. The access point may decode the proberequest to determine whether neighbor report information is requested.

Then, at block 1220, the access point generates a probe response inresponse to and based on the probe request. The access point mayconditionally include neighbor report information in the probe responsebased decoding whether an indication or absence of an indication is inthe probe request. For example, the access point 104 can determinewhether or not the probe request 1120 includes an indication thatneighbor report information should be sent, and can include or omit theneighbor report information accordingly.

Thereafter, at block 1240, the access point transmits the probe responseto a wireless device. For example, the access point 104 can transmit theprobe response 1130 including neighbor report information to thewireless device 106 if it was requested by the probe request. Inembodiments where the wireless device 106 already has neighbor reportinformation and transmits the probe request 1140 omitting the neighborreport information request, the access point 104 can transmit the proberesponse 1150 omitting the neighbor report information.

Some aspects of process 1200 include transmitting a beacon having noneighbor report information. For example, since neighbor reportinformation is being provided b a device performing process 1200 via theprobe response message described above when requested, there may be noneed to include the neighbor report information in the beacon. Thisreduces the size of the beacon, thus saving capacity of the wirelessmedium for other purposes.

In an embodiment, the method shown in FIG. 10 can be implemented in awireless device that can include a receiving circuit, a generatingcircuit, and a transmitting circuit. Those skilled in the art willappreciate that a wireless device can have more components than thesimplified wireless device described herein. The wireless devicedescribed herein includes only those components useful for describingsome prominent features of implementations within the scope of theclaims.

The receiving circuit can be configured to receive the probe request. Insome embodiments, the receiving circuit can be configured to perform atleast block 1210 of FIG. 10. The receiving circuit can include one ormore of the processor 404 (FIG. 2), the receiver 412 (FIG. 2), theantenna 416 (FIG. 2), and the transceiver 414 (FIG. 2). In someimplementations, means for receiving can include the receiving circuit.

The generating circuit can be configured to generate the probe response.In some embodiments, the generating circuit can be configured to performat least block 1220 of FIG. 10. The generating circuit can include oneor more of the processor 404 (FIG. 2), the DSP 420, the signal detector418 (FIG. 2), and the memory 406 (FIG. 2). In some implementations,means for generating can include the generating circuit.

The transmitting circuit can be configured to transmit the proberesponses. In some embodiments, the transmitting circuit can beconfigured to perform at least block 1240 of FIG. 10. The transmittingcircuit can include one or more of the processor 404 (FIG. 2), thetransmitter 410 (FIG. 2), the antenna 416 (FIG. 2), and the transceiver414 (FIG. 2). In some implementations, means for transmitting caninclude the transmitting circuit.

FIG. 11 shows a flowchart 1300 for an exemplary method of wirelesscommunication that can be employed within the wireless communicationsystem 1100 of FIG. 9. The method can be implemented in whole or in partby the devices described herein, such as the wireless device 402 shownin FIG. 2. Although the illustrated method is described herein withreference to the wireless communication system 130 discussed above withrespect to FIG. 1, the wireless communication systems 1100 discussedabove with respect to FIG. 9, and the wireless device 402 discussedabove with respect to FIG. 2, a person having ordinary skill in the artwill appreciate that the illustrated method can be implemented byanother device described herein, or any other suitable device. Althoughthe illustrated method is described herein with reference to aparticular order, in various embodiments, blocks herein can be performedin a different order, or omitted, and additional blocks can be added.

Method 1300 may be utilized by two devices communicating on a wirelessnetwork to reduce the amount of data transmitted between them. Forexample, known methods may transmit beacon frames that include neighborreport information. As beacon transmissions occur frequently, someportion of a wireless medium capacity may be consumed by thetransmission of neighbor report information included in beacon frames,where the neighbor report information included in the beacon frames isessentially not utilized by many devices receiving the information. Forexample, many devices receiving the neighbor report information mayalready have received it from previous beacon frames. Therefore,inclusion of the neighbor report information is beacon frames mayconsume capacity of a wireless medium that may be better used for otherpurposes. Method 1300 provides a method to decode neighbor reportinformation from a probe response message, and request the informationwhen needed. This may reduce the total number of transmissions ofneighbor report information on a wireless network, thus freeing capacityof the wireless network for other uses.

First, at block 1310, the wireless device determines whetherneighborhood report information is stored. For example, the wirelessdevice 106 can determine whether the memory 406 stores neighborhoodreport information for the network of the access point 104. In someembodiments, the wireless device 106 can only consider recentneighborhood report information, for example that which has beenreceived within a threshold amount of time.

Next, at block 1320, the wireless device transmits a probe requestconditionally including a request for neighbor report information basedon said determining. For example, if the wireless device 106 determinesthat neighbor report information is needed, it can transmit the proberequest 1120 including a request for neighbor report information. If thewireless device 106 determines that neighbor report information is notneeded, it can transmit the probe request 1140 omitting the request forneighbor report information.

Then, at block 1330, the wireless device receives a probe response. Theprobe response may include the neighbor report information when theprobe request includes the request for neighbor report information. Forexample, the wireless device 106 can receive the probe response 1130including the neighbor report information in response to the proberequest 1120. The wireless device 106 can receive the probe response1150 omitting the neighbor report information in response to the proberequest 1140.

In block 1335, the probe response is decoded to determine whetherneighbor report information is included in the probe response. If theinformation is included, it may be stored in block 1340.

In an embodiment, the method shown in FIG. 11 can be implemented in awireless device that can include a determining circuit, a transmittingcircuit, a receiving circuit, a decoding circuit, and a storing circuit.Those skilled in the art will appreciate that a wireless device can havemore components than the simplified wireless device described herein.The wireless device described herein includes only those componentsuseful for describing some prominent features of implementations withinthe scope of the claims.

The determining circuit can be configured to determine whetherneighborhood report information is stored. In some embodiments, thedetermining circuit can be configured to perform at least block 1310 ofFIG. 11. The determining circuit can include one or more of theprocessor 404 (FIG. 2), the DSP 420, the signal detector 418 (FIG. 2),the receiver 412 (FIG. 2), and the memory 406 (FIG. 2). In someimplementations, means for determining can include the determiningcircuit.

The transmitting circuit can be configured to transmit the proberequest. In some embodiments, the transmitting circuit can be configuredto perform at least block 1320 of FIG. 11. The transmitting circuit caninclude one or more of the processor 404 (FIG. 2), the transmitter 410(FIG. 2), the antenna 416 (FIG. 2), and the transceiver 414 (FIG. 2). Insome implementations, means for transmitting can include thetransmitting circuit.

The receiving circuit can be configured to receive the probe response.In some embodiments, the receiving circuit can be configured to performat least block 1320 of FIG. 11. The receiving circuit can include one ormore of the processor 404 (FIG. 2), the receiver 412 (FIG. 2), theantenna 416 (FIG. 2), and the transceiver 414 (FIG. 2). In someimplementations, means for receiving can include the receiving circuit.

The decoding circuit can be configured to decode the probe response todetermine whether neighbor report information is included in the proberesponse. In some embodiments, the decoding circuit can be configured toperform at least block 1335 of FIG. 11. The decoding circuit can includeone or more of the processor 404 (FIG. 2), the DSP 420, the signaldetector 418 (FIG. 2), the receiver 412 (FIG. 2), and the memory 406(FIG. 2). In some implementations, means for decoding can include thedetermining circuit.

The storing circuit can be configured to store the neighbor reportinformation if it is included in the probe response. In someembodiments, the storing circuit can be configured to perform at leastblock 1340 of FIG. 11. The storing circuit can include one or more ofthe processor 404 (FIG. 2), the DSP 420, the signal detector 418 (FIG.2), the receiver 412 (FIG. 2), and the memory 406 (FIG. 2). In someimplementations, means for storing can include the storing circuit.

Shared Wireless Device State Information

As discussed above, in various embodiments, a large amount of channeltime can be consumed by beacons and probe responses. This can beparticularly true in dense networks. In one embodiment, channel time canbe reduced by omitting at least some data shared between probe requestsand association requests. Reduced channel time can increase overallnetwork efficiency. In some embodiments, the access point can store theshared data and can indicate a timeout period during which the shareddata will be maintained.

FIG. 12 shows an embodiment of the wireless communication system 1400 inwhich aspects of the present disclosure may be employed. As shown, thewireless communication system 1400 includes the access point 104 and awireless device 106. The wireless communication system 1400 can besimilar to the wireless communication system 100, described above withrespect to FIG. 1. For example, the access point 104 can include theaccess point 104 shown in FIG. 1, and the wireless device 106 caninclude any of the wireless devices 106 a-106 d shown in FIG. 1. Invarious embodiments, the access point 104 and/or the wireless device 106can include the wireless device 402 (FIG. 2) or any other suitabledevice.

FIG. 12 illustrates an exemplary communication exchange between theaccess point 104 and the wireless device 106. In the illustratedcommunication exchange, the access point 104 can be configured to storeshared data and indicate a timeout period. Although the illustratedcommunications are shown and described herein with reference to aparticular order, in various embodiments, communication herein can beperformed in a different order, or omitted, and additionalcommunications can be added.

First, the wireless device 106 transmits a probe request 1410 includingshared wireless device state information. In some embodiments, sharedwireless device information can include indications of one or more of:shared rates, extended supported rates, supported operating classes,high-throughput (HT) capabilities, 20/40 basic service set (BSS)coexistence, and extended capabilities. The probe request can furtherinclude indications of one or more of: a service set identification(SSID), an information request, a direct-sequence spread spectrum (DSSS)parameter set, an SSID list, a channel usage, an interworkingindication, and a mesh identification. The access point 104 can storethe shared wireless device state information, for example in the memory406 (FIG. 2).

Upon reception of the probe request, the access point 104 may respondwith an ACK including an indication that the information was stored.Then, the access point 104 transmits a probe response 1420 including atimeout period. The timeout period can indicate how long the accesspoint 104 will store the shared wireless device information. When theaccess point 104 receives frames from the wireless device 106 within thetimeout period, the access point 104 can associate the received framewith the shared wireless device information. Thus, the shared wirelessdevice information can be omitted from the frame. After the timeoutperiod, however, the access point 104 can discard the shared wirelessdevice information.

For example, the wireless device 106 can transmit an association request1430 within the timeout period. Thus, the association request 1430 canomit some or all of the shared wireless device information. In someembodiments, the association request 1430 can include indications of oneor more of: a capability, a listen interval, a service setidentification (SSID), supported channels, a robust security network(RSN) indication, a quality-of-service (QoS) capability, RM enabledcapabilities, a mobility domain, and a QoS traffic capability. Theaccess point 104 can read the shared wireless device information frommemory 406 (FIG. 2) and can respond with an association response 1440.

On the other hand, the wireless device 106 can transmit an associationrequest 1450 outside the timeout period. Thus, the association request1430 can include some or all of the shared wireless device information.The access point 104 can read the shared wireless device informationfrom the association request 1450 and can respond with an associationresponse 1460.

FIG. 13 shows a flowchart 1500 for an exemplary method of wirelesscommunication that can be employed within the wireless communicationsystem 1400 of FIG. 12. The method can be implemented in whole or inpart by the devices described herein, such as the wireless device 402shown in FIG. 2. Although the illustrated method is described hereinwith reference to the wireless communication system 150 discussed abovewith respect to FIG. 1, the wireless communication systems 1400discussed above with respect to FIG. 12, and the wireless device 402discussed above with respect to FIG. 2, a person having ordinary skillin the art will appreciate that the illustrated method can beimplemented by another device described herein, or any other suitabledevice. Although the illustrated method is described herein withreference to a particular order, in various embodiments, blocks hereincan be performed in a different order, or omitted, and additional blockscan be added.

First, at block 1510, the access point receives a probe request Forexample, the access point 104 can receive the probe request 1410 thatincludes shared wireless device state information from the wirelessdevice 106.

At block 1515, the access point decodes the probe request to determinethe shared wireless device state information. For example, the accesspoint may be configured to parse the probe request to determine alocation of the shared wireless state information within the proberequest. In some aspects, the access point decodes the shared wirelessstate information to determine one or more of: shared rates, extendedsupported rates, supported operating classes, high-throughput (HT)capabilities, 20/40 basic service set (BSS) coexistence, and extendedcapabilities. In some aspects, the access point decodes the proberequest to determine one or more of: a service set identification(SSID), an information request, a direct-sequence spread spectrum (DSSS)parameter set, an SSID list, a channel usage, an interworkingindication, and a mesh identification.

Then, at block 1520, the access point can store the shared wirelessdevice state information for at least a timeout period. For example, theaccess point 104 can store the shared wireless device state informationin the memory 406. After the timeout period expires, the access point104 can expire, erase, or otherwise discard the shared wireless devicestate information.

Next, at block 1530, the access point transmits a probe responseindicating the timeout period. For example, the access point 104 cantransmit the probe response 1420 to the wireless device 106. The proberesponse 1420 can include the timeout period, for example, as aninformation element.

Thereafter, at block 1540, the access point receives an associationrequest omitting the wireless device state information within thetimeout period. For example, the access point 104 can receive theassociation request 1430 from the wireless device 106. The access point104 can retrieve the shared wireless device state information from thememory 406 and can respond with the association response 1440. In someaspects, the access point may decode the association request todetermine one or more of: a capability, a listen interval, a service setidentification (SSID), supported channels, a robust security network(RSN) indication, a quality-of-service (QoS) capability, RM enabledcapabilities, a mobility domain, and a QoS traffic capability.

In other embodiments, as discussed above, the access point 104 canreceive a second association request 1450 outside the timeout period. Insome aspects, the second association request received outside thetimeout period may include the shared state information. In theseaspects, association requests received outside the timeout period can bedecoded to determine updated shared state information. An associationresponse may then be generated based on the updated shared stateinformation received in the second association request. In some aspects,this is shown by association response 1460 in FIG. 12.

In an embodiment, the method shown in FIG. 13 can be implemented in awireless device that can include a receiving circuit, a decodingcircuit, a storing circuit, and a transmitting circuit. Those skilled inthe art will appreciate that a wireless device can have more componentsthan the simplified wireless device described herein. The wirelessdevice described herein includes only those components useful fordescribing some prominent features of implementations within the scopeof the claims.

The receiving circuit can be configured to receive the probe requestand/or association request. In some embodiments, the receiving circuitcan be configured to perform at least blocks 1510, and/or 1540 of FIG.13. The receiving circuit can include one or more of the processor 404(FIG. 2), the receiver 412 (FIG. 2), the antenna 416 (FIG. 2), and thetransceiver 414 (FIG. 2). In some implementations, means for receivingcan include the receiving circuit.

The decoding circuit can be configured to decode the probe request todetermine the shared wireless device state information. In someembodiments, the decoding circuit can be configured to perform at leastblock 1515 of FIG. 13. The decoding circuit can include one or more ofthe processor 404 (FIG. 2), receiver 412 (FIG. 2), the antenna 416 (FIG.2), and/or the transceiver 414 (FIG. 2). In some implementations, meansfor decoding can include the decoding circuit.

The storing circuit can be configured to store the shared wirelessdevice state information. In some embodiments, the storing circuit canbe configured to perform at least block 1520 of FIG. 13. The storingcircuit can include one or more of the processor 404 (FIG. 2), the DSP420, and the memory 406 (FIG. 2). In some implementations, means forstoring can include the storing circuit.

The transmitting circuit can be configured to transmit the proberesponses. In some embodiments, the transmitting circuit can beconfigured to perform at least block 1530 of FIG. 13. The transmittingcircuit can include one or more of the processor 404 (FIG. 2), thetransmitter 410 (FIG. 2), the antenna 416 (FIG. 2), and the transceiver414 (FIG. 2). In some implementations, means for transmitting caninclude the transmitting circuit.

FIG. 14 shows a flowchart 1600 for an exemplary method of wirelesscommunication that can be employed within the wireless communicationsystem 1400 of FIG. 12. The method can be implemented in whole or inpart by the devices described herein, such as the wireless device 402shown in FIG. 2. Although the illustrated method is described hereinwith reference to the wireless communication system 160 discussed abovewith respect to FIG. 1, the wireless communication systems 1400discussed above with respect to FIG. 12, and the wireless device 402discussed above with respect to FIG. 2, a person having ordinary skillin the art will appreciate that the illustrated method can beimplemented by another device described herein, or any other suitabledevice. Although the illustrated method is described herein withreference to a particular order, in various embodiments, blocks hereincan be performed in a different order, or omitted, and additional blockscan be added.

First, at block 1610, the wireless device transmits a probe requestincluding shared wireless device state information. For example, thewireless device 106 can transmit the probe request 1410 to the accesspoint 104. The shared wireless device state information can includeinformation shared between one or more wireless communication frames,such as conventional probe requests and association requests. In someaspects, the shared wireless state information is generated to includeindications of one or more of: shared rates, extended supported rates,supported operating classes, high-throughput (HT) capabilities, 20/40basic service set (BSS) coexistence, and extended capabilities. Byomitting the shared wireless device state information from at least oneframe, network traffic can be reduced. In some aspects, the proberequest to generated to include indications of one or more of: a serviceset identification (SSID), an information request, a direct-sequencespread spectrum (DSSS) parameter set, an SSID list, a channel usage, aninterworking indication, and a mesh identification. By omitting theshared wireless device state information from at least one frame,network traffic can be reduced.

Then, at block 1620, the wireless device receives a probe response. Inblock 1625, the probe response is decoded to determine a timeout period.For example, the wireless device 106 can receive the probe response 1420from the access point 104. The timeout period can indicate how long theaccess point 104 will store the shared wireless device stateinformation.

Next, at block 1630, the wireless device transmits an associationrequest omitting the wireless device state information within thetimeout period. For example, the wireless device 106 can transmit theassociation request 1430 and can receive the association response 1440.In some aspects, the association request is generated to includeindications of one or more of: a capability, a listen interval, aservice set identification (SSID), supported channels, a robust securitynetwork (RSN) indication, a quality-of-service (QoS) capability, RMenabled capabilities, a mobility domain, and a QoS traffic capability.As discussed above, in other embodiments, the wireless device 106 cantransmit a second association request (such as association request 1450)outside the timeout period. Thus, the second association request 1450can include the shared wireless device state information in response tothe second association request being transmitted outside the timeoutperiod.

In an embodiment, the method shown in FIG. 14 can be implemented in awireless device that can include a decoding circuit, transmittingcircuit and a receiving circuit. Those skilled in the art willappreciate that a wireless device can have more components than thesimplified wireless device described herein. The wireless devicedescribed herein includes only those components useful for describingsome prominent features of implementations within the scope of theclaims.

The transmitting circuit can be configured to transmit the probe requestand/or association request. In some embodiments, the transmittingcircuit can be configured to perform at least blocks 1610 and/or 1630 ofFIG. 14. The transmitting circuit can include one or more of theprocessor 404 (FIG. 2), the transmitter 410 (FIG. 2), the antenna 416(FIG. 2), and the transceiver 414 (FIG. 2). In some implementations,means for transmitting can include the transmitting circuit.

The receiving circuit can be configured to receive the probe response.In some embodiments, the receiving circuit can be configured to performat least block 1620 of FIG. 14. The receiving circuit can include one ormore of the processor 404 (FIG. 2), receiver 412 (FIG. 2), the antenna416 (FIG. 2), and the transceiver 414 (FIG. 2). In some implementations,means for receiving can include the receiving circuit.

The decoding circuit can be configured to decode the probe response. Insome embodiments, the decoding circuit can be configured to perform atleast block 1625 of FIG. 14. The decoding circuit can include one ormore of the processor 404 (FIG. 2), receiver 412 (FIG. 2), the antenna416 (FIG. 2), and the transceiver 414 (FIG. 2). In some implementations,means for decoding can include the decoding circuit.

Shared Access Point State Information

As discussed above, in various embodiments, a large amount of channeltime can be consumed by beacons and probe responses. This can beparticularly true in dense networks. In one embodiment, channel time canbe reduced by omitting at least some data shared between probe responsesand association responses. Reduced channel time can increase overallnetwork efficiency. In some embodiments, the wireless device can storethe shared data and can transmit an indication that the shared data ismaintained.

FIG. 15 shows an embodiment of the wireless communication system 1700 inwhich aspects of the present disclosure may be employed. As shown, thewireless communication system 1700 includes the access point 104 and awireless device 106. The wireless communication system 1700 can besimilar to the wireless communication system 100, described above withrespect to FIG. 1. For example, the access point 104 can include theaccess point 104 shown in FIG. 1, and the wireless device 106 caninclude any of the wireless devices 106 a-106 d shown in FIG. 1. Invarious embodiments, the access point 104 and/or the wireless device 106can include the wireless device 402 (FIG. 2) or any other suitabledevice.

FIG. 15 illustrates an exemplary communication exchange between theaccess point 104 and the wireless device 106. In the illustratedcommunication exchange, the wireless device 106 be configured to storeshared access point data and can transmit an indication that the shareddata is maintained. Although the illustrated communications are shownand described herein with reference to a particular order, in variousembodiments, communication herein can be performed in a different order,or omitted, and additional communications can be added.

First, the wireless device 106 transmits a probe request 1710. In someembodiments, the probe request 1710 can include an indication that thewireless device 106 has stored shared access point information. Thewireless device 106 can have gathered the shared access pointinformation by earlier reception of beacon frames or probe responsessent by the access point 104. The beacon frames or probe responses canadditionally include an indication of the version of the information.Such indication can, for example, include a sequence number that isincremented or otherwise modified every time the information changes.

Shared access point information can include at least some access pointinformation common to at least two communication frames such as, forexample, probe responses and association responses. In some embodiments,shared information can include indications of one or more of: sharedrates, extended supported rates, supported operating classes,high-throughput (FIT) capabilities, 20/40 basic service set (BSS)coexistence, and extended capabilities. The probe request can furtherinclude indications of one or more of: a service set identification(SSID), an information request, a direct-sequence spread spectrum (DSSS)parameter set, an SSID list, a channel usage, an interworkingindication, and a mesh identification.

When the wireless device 106 indicates that it has stored shared accesspoint information, the access point 104 may omit that information fromone or more frames. The indication that device 106 has stored the sharedinformation can include an indication of the version of the storedinformation, such as a sequence number of the information. In theillustrated embodiment, the wireless device 106 has not yet storedshared access point information.

Then, the access point 104 transmits a probe response 1720 including theshared access point information. The wireless device 106 stores theshared access point information, for example in the memory 406 (FIG. 2).In some embodiments, the wireless device 106 can expire, delete, orotherwise discard shared access point information after a timeoutperiod. In other embodiments, the wireless device 106 can discard sharedaccess point information after receiving an indication from the accesspoint 104 that the shared access point information has changed.

Next, the wireless device 106 can transmit an association request 1730.The association request 1730 can indicate to the access point 104 thatthe wireless device 106 has stored the shared access point information.Thus, the access point 104 can respond with an association response 1740omitting the shared access point information

On the other hand, in another embodiment, the wireless device 106 cantransmit an association request not indicating that shared access pointinformation has been stored (not shown). Thus, the access point 104 canrespond with an association request including some or all shared accesspoint information (not shown).

In some aspects, the association request 1730 may indicate a version ofthe shared access point information that is stored by the wirelessdevice 106. The access point 104 may then include the shared accesspoint information in the association request if it has a newer versionof the shared access point information than indicated in the associationrequest.

FIG. 16 shows a flowchart 1800 for an exemplary method of wirelesscommunication that can be employed within the wireless communicationsystem 1700 of FIG. 15. The method can be implemented in whole or inpart by the devices described herein, such as the wireless device 402shown in FIG. 2. Although the illustrated method is described hereinwith reference to the wireless communication system 180 discussed abovewith respect to FIG. 1, the wireless communication systems 1700discussed above with respect to FIG. 15, and the wireless device 402discussed above with respect to FIG. 2, a person having ordinary skillin the art will appreciate that the illustrated method can beimplemented by another device described herein, or any other suitabledevice. Although the illustrated method is described herein withreference to a particular order, in various embodiments, blocks hereincan be performed in a different order, or omitted, and additional blockscan be added.

First, at block 1810, the access point receives a probe request. Forexample, the access point 104 can receive the probe request 1710 fromthe wireless device 106.

Then, at block 1820, the access point transmits a probe responseincluding shared access point information. For example, the access point104 can transmit the probe response 1720 to the wireless device 106. Theprobe response 1720 can include the shared access point information. Insome aspects, the probe response also includes version information forthe shared access point information included in the probe response. Theprobe response may also be generated to include an identifier. Theidentifier may be associated with the shared access point information.In some aspects, the identifier is generated to include one or more of:an explicit identifier in an information element; an implicit identifiercomprising a media access control (MAC) address of the access point, animplicit identifier comprising a MAC sequence number of the proberesponse, an implicit identifier comprising a timestamp of the proberesponse, an implicit identifier comprising a checksum of the proberesponse, and an implicit identifier comprising the last 4 bytes of theprobe response.

In some aspects, the shared access point state information for the proberesponse is generated to include indications of one or more of: sharedrates, extended supported rates, supported operating classes,high-throughput (HT) capabilities, 20/40 basic service set (BSS)coexistence, and extended capabilities.

Thereafter, at block 1830, the access point receives an associationrequest including an indication that the wireless device has stored theshared access point information. In some aspects, the indication mayindicate whether the shared access point information is stored or not.In other aspects, the indication may further indicate a version ofshared access point information stored by the wireless device. Forexample, the access point 104 can receive the association request 1730from the wireless device 106. Thus, the access point 104 can determinethat any association response can omit at least some shared access pointinformation.

In some aspects, the association request may be decoded to determine aversion of shared access point information stored by the wirelessdevice, and determine whether a version of shred access pointinformation available to the access point is newer than the versionstored by the device. If the access point has newer information, it maychoose to include the newer information in the association response(below).

Next, in block 1840, the access point can transmit an associationresponse conditionally including the shared access point informationbased on the indication in the association request. For example, in someaspects the access point includes the shared access point information inthe association response if the wireless device indicated it has notstored access point state information, and does not include the sharedaccess point information in the association response if the wirelessdevice indicates it has stored the information. In other aspects, theindication in the association request may include version informationfor shared access point state information stored by the wireless device.In these aspects, the access point may compare a version of sharedaccess point state information available to the access point against theversion provided in the association request. If the version available tothe access point is newer, the access point may include the sharedaccess point information it has available in the association response,and not include it otherwise.

For example, the access point 104 can transmit the association response1740 to the wireless device 1740. In other embodiments, as discussedabove, the access point 104 can transmit an association responseincluding at least some shared access point information when theassociation request does not include an indication that the sharedaccess point information is stored.

In some aspects, the access point 104 can determine whether the versionof the shared information stored by the wireless device is older than aversion of shared information available to the access point. In someaspects, the access point may then generate the association response toinclude the newer version of the shared access point information basedon the version stored by the wireless device and the version availableto the access point.

In an embodiment, the method shown in FIG. 16 can be implemented in awireless device that can include a receiving circuit and a transmittingcircuit. Those skilled in the art will appreciate that a wireless devicecan have more components than the simplified wireless device describedherein. The wireless device described herein includes only thosecomponents useful for describing some prominent features ofimplementations within the scope of the claims.

The receiving circuit can be configured to receive the probe requestand/or association request. In some embodiments, the receiving circuitcan be configured to perform at least blocks 1810 and/or 1830 of FIG.16. The receiving circuit can include one or more of the receiver 412(FIG. 2), the antenna 416 (FIG. 2), and the transceiver 414 (FIG. 2). Insome implementations, means for receiving can include the receivingcircuit.

The transmitting circuit can be configured to transmit the proberesponse and/or association response. In some embodiments, thetransmitting circuit can be configured to perform at least blocks 1820and/or 1840 of FIG. 16. The transmitting circuit can include one or moreof the transmitter 410 (FIG. 2), the antenna 416 (FIG. 2), and thetransceiver 414 (FIG. 2). In some implementations, means fortransmitting can include the transmitting circuit.

FIG. 17 shows a flowchart 1900 for an exemplary method of wirelesscommunication that can be employed within the wireless communicationsystem 1700 of FIG. 15. The method can be implemented in whole or inpart by the devices described herein, such as the wireless device 402shown in FIG. 2. Although the illustrated method is described hereinwith reference to the wireless communication system 190 discussed abovewith respect to FIG. 1, the wireless communication systems 1700discussed above with respect to FIG. 15, and the wireless device 402discussed above with respect to FIG. 2, a person having ordinary skillin the art will appreciate that the illustrated method can beimplemented by another device described herein, or any other suitabledevice. Although the illustrated method is described herein withreference to a particular order, in various embodiments, blocks hereincan be performed in a different order, or omitted, and additional blockscan be added.

First, at block 1910, the wireless device transmits a probe request. Forexample, the wireless device 106 can transmit the probe request 1710 tothe access point 104.

Then, at block 1920, the wireless device receives a probe responseincluding shared access point information. For example, the wirelessdevice 106 can receive the probe response 1720 from the access point104. The shared access point information can include information sharedbetween one or more wireless communication frames, such as conventionalprobe responses and association responses. By omitting the shared accesspoint state information from at least one frame, network traffic can bereduced.

Thereafter, at block 1930, the wireless device stores the shared accesspoint information. For example, the wireless device 106 can store theshared access point information in the memory 406.

Next, at block 1940, the wireless device transmits an associationrequest indicating that the shared access point information is stored.For example, the wireless device 106 can transmit the associationrequest 1730. In some aspects, the wireless device transmits a versionof the shared access point information that is stored. This may assistthe access point in determining whether it should send shared accesspoint information back to the wireless device in the associationresponse.

Subsequently, at block 1950, the wireless device receives an associationresponse omitting the shared access point information. For example, thewireless device 106 can receive the association response 1740 from theaccess point 104. As discussed above, in other embodiments, the wirelessdevice 106 can transmit the association request without an indicationthat the shared access point information has been stored, for example inembodiments where the wireless device 106 has not yet received theshared access point information, the shared access point information isstale, etc. Thus, the wireless device can receive an associationresponse including at least some shared access point information.

In block 1960, the association response is decoded to determine whetherthe association response includes shared access point information. If itdoes, the device performing process 1900 may store the shared accesspoint information contained in the association response.

In an embodiment, the method shown in FIG. 17 can be implemented in awireless device that can include a transmitting circuit, a storingcircuit, and a receiving circuit. Those skilled in the art willappreciate that a wireless device can have more components than thesimplified wireless device described herein. The wireless devicedescribed herein includes only those components useful for describingsome prominent features of implementations within the scope of theclaims.

The transmitting circuit can be configured to transmit the probe requestand/or association request. In some embodiments, the transmittingcircuit can be configured to perform at least blocks 1910 and/or 1930 ofFIG. 17. The transmitting circuit can include one or more of theprocessor 404 (FIG. 2), transmitter 410 (FIG. 2), the antenna 416 (FIG.2), and the transceiver 414 (FIG. 2). In some implementations, means fortransmitting can include the transmitting circuit.

The storing circuit can be configured to store the shared wirelessdevice state information. In some embodiments, the storing circuit canbe configured to perform at least block 1920 of FIG. 17. The storingcircuit can include one or more of the processor 404 (FIG. 2), the DSP420, and the memory 406 (FIG. 2). In some implementations, means forstoring can include the storing circuit.

The receiving circuit can be configured to receive the probe response.In some embodiments, the receiving circuit can be configured to performat least block 1940 of FIG. 17. The receiving circuit can include one ormore of the processor 404 (FIG. 2), receiver 412 (FIG. 2), the antenna416 (FIG. 2), and the transceiver 414 (FIG. 2). In some implementations,means for receiving can include the receiving circuit.

As used herein, the term “determining” encompasses a wide variety ofactions. For example, “determining” may include calculating, computing,processing, deriving, investigating, looking up (e.g., looking up in atable, a database or another data structure), ascertaining and the like.Also, “determining” may include receiving (e.g., receiving information),accessing (e.g., accessing data in a memory) and the like. Also,“determining” may include resolving, selecting, choosing, establishingand the like. Further, a “channel width” as used herein may encompass ormay also be referred to as a bandwidth in certain aspects.

As used herein, a phrase referring to “at least one of” a list of itemsrefers to any combination of those items, including single members. Asan example, “at least one of: a, b, or c” is intended to cover: a, b, c,a-b, a-c, b-c, and a-b-c.

The various operations of methods described above may be performed byany suitable means capable of performing the operations, such as varioushardware and/or software component(s), circuits, and/or module(s).Generally, any operations illustrated in the Figures may be performed bycorresponding functional means capable of performing the operations.

The various illustrative logical blocks, modules and circuits describedin connection with the present disclosure may be implemented orperformed with a general purpose processor, a digital signal processor(DSP), an application specific integrated circuit (ASIC), a fieldprogrammable gate array signal (FPGA) or other programmable logic device(PLD), discrete gate or transistor logic, discrete hardware componentsor any combination thereof designed to perform the functions describedherein. A general purpose processor may be a microprocessor, but in thealternative, the processor may be any commercially available processor,controller, microcontroller or state machine. A processor may also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration.

In one or more aspects, the functions described may be implemented inhardware, software, firmware, or any combination thereof. If implementedin software, the functions may be stored on or transmitted over as oneor more instructions or code on a computer-readable medium.Computer-readable media includes both computer storage media andcommunication media including any medium that facilitates transfer of acomputer program from one place to another. A storage media may be anyavailable media that can be accessed by a computer. By way of example,and not limitation, such computer-readable media can comprise RAM, ROM,EEPROM, CD-ROM or other optical disk storage, magnetic disk storage orother magnetic storage devices, or any other medium that can be used tocarry or store desired program code in the form of instructions or datastructures and that can be accessed by a computer. Also, any connectionis properly termed a computer-readable medium. For example, if thesoftware is transmitted from a website, server, or other remote sourceusing a coaxial cable, fiber optic cable, twisted pair, digitalsubscriber line (DSL), or wireless technologies such as infrared, radio,and microwave, then the coaxial cable, fiber optic cable, twisted pair,DSL, or wireless technologies such as infrared, radio, and microwave areincluded in the definition of medium. Disk and disc, as used herein,includes compact disc (CD), laser disc, optical disc, digital versatiledisc (DVD), floppy disk, and Blu-ray® disc where disks usually reproducedata magnetically, while discs reproduce data optically with lasers.Thus, in some aspects, computer readable medium may comprisenon-transitory computer readable medium (e.g., tangible media). Inaddition, in some aspects computer readable medium may comprisetransitory computer readable medium (e.g., a signal). Combinations ofthe above should also be included within the scope of computer-readablemedia.

Thus, certain aspects may comprise a computer program product forperforming the operations presented herein. For example, such a computerprogram product may comprise a computer readable medium havinginstructions stored (and/or encoded) thereon, the instructions beingexecutable by one or more processors to perform the operations describedherein. For certain aspects, the computer program product may includepackaging material.

The methods disclosed herein comprise one or more steps or actions forachieving the described method. The method steps and/or actions may beinterchanged with one another without departing from the scope of theclaims. In other words, unless a specific order of steps or actions isspecified, the order and/or use of specific steps and/or actions may bemodified without departing from the scope of the claims.

Software or instructions may also be transmitted over a transmissionmedium. For example, if the software is transmitted from a website,server, or other remote source using a coaxial cable, fiber optic cable,twisted pair, digital subscriber line (DSL), or wireless technologiessuch as infrared, radio, and microwave, then the coaxial cable, fiberoptic cable, twisted pair, DSL, or wireless technologies such asinfrared, radio, and microwave are included in the definition oftransmission medium.

Further, it should be appreciated that modules and/or other appropriatemeans for performing the methods and techniques described herein can bedownloaded and/or otherwise obtained by a user terminal and/or basestation as applicable. For example, such a device can be coupled to aserver to facilitate the transfer of means for performing the methodsdescribed herein. Alternatively, various methods described herein can beprovided via storage means (e.g., RAM, ROM, a physical storage mediumsuch as a compact disc (CD) or floppy disk, etc.), such that a userterminal and/or base station can obtain the various methods uponcoupling or providing the storage means to the device. Moreover, anyother suitable technique for providing the methods and techniquesdescribed herein to a device can be utilized.

It is to be understood that the claims are not limited to the preciseconfiguration and components illustrated above. Various modifications,changes and variations may be made in the arrangement, operation anddetails of the methods and apparatus described above without departingfrom the scope of the claims.

While the foregoing is directed to aspects of the present disclosure,other and further aspects of the disclosure may be devised withoutdeparting from the basic scope thereof, and the scope thereof isdetermined by the claims that follow.

What is claimed is:
 1. In a communication system including at least anaccess point and a plurality of wireless devices transmitting respectiveprobe requests to the access point for determining whether the accesspoint is within a range for initiating and maintaining a wirelesscommunication link between each of the plurality of wireless devices andthe access point, a method for station selection of a modulation andcoding rate for more efficient probe communication, the methodcomprising: transmitting, at the access point, one or more frames to theplurality of wireless devices, each frame comprising a transmissionpower indication; receiving, at the access point, the respective proberequests from the plurality of wireless devices at a respective receivedpower; determining a respective path-loss for each of the respectiveprobe requests based on the respective received power; determining arespective modulation and coding scheme for each of the plurality ofwireless devices based on the respective path-loss; transmitting, at theaccess point, separate first responses to the respective probe requeststo the plurality of wireless devices, each of the probe responsestransmitted according to the respective modulation and coding scheme;receiving acknowledgments of the first responses to the respective proberequests from a first portion of the plurality of wireless devices;determining no acknowledgments of the first responses to the respectiveprobe requests have been received from a second portion of the pluralityof wireless devices within a predetermined time period aftertransmission of the corresponding first responses to the respectiveprobe requests; determining second modulation and coding schemes for thesecond portion of wireless devices based on the determining, each secondmodulation and coding scheme defining a coding rate that is lower than acoding rate used for the first response transmitted to the respectivewireless device in the second portion; transmitting, at the accesspoint, separate second responses to the respective probe requests to thewireless devices in the second portion, each of the second proberesponses transmitted according to the corresponding second modulationand coding scheme; and utilizing the modulation and coding schemes ofprobe responses acknowledged by wireless devices of the plurality ofwireless devices for subsequent communication with the wireless devices.2. The method of claim 1, wherein the transmitting of the one or moreframes comprises at least one of: transmitting a beacon, transmitting ashort beacon, and transmitting a broadcast probe response.
 3. In acommunication system including at least an access point and a pluralityof wireless devices transmitting respective probe requests to the accesspoint for determining whether the access point is within a range forinitiating and maintaining a wireless communication link between each ofthe plurality of wireless devices and the access point, an apparatus formore efficient probe communication, comprising: the access point, theaccess point comprising: a transmitter configured to transmit one ormore frames each comprising a transmission power indication, and areceiver configured to receive the respective probe requests from theplurality of wireless devices, each of the respective probe requestsreceived at a respective received power; an electronic hardwareprocessor, configured to: determine a respective path-loss for each ofthe respective probe requests based on the respective received power,and determine a respective modulation and coding scheme for each of theplurality of wireless devices based on the respective path-loss, whereinthe transmitter is further configured to transmit separate firstresponses to the respective probe requests to the plurality of wirelessdevices, each of the probe responses transmitted according to themodulation and coding scheme used to receive the respective proberequest, wherein the receiver is further configured to receiveacknowledgments of the first responses to the respective probe requestsfrom a first portion of the plurality of wireless devices, wherein theelectronic hardware processor is further configured to determine noacknowledgments of the first responses to the respective probe requestshave been received from a second portion of the plurality of wirelessdevices within a predetermined time period after transmission of thecorresponding first responses to the respective probe requests, whereinthe electronic hardware processor is further configured to determinesecond modulation and coding schemes for the second portion based on thedetermining, each second modulation and coding scheme defining a codingrate that is lower than a coding rate used for the first responsetransmitted to a respective wireless device in the second portion,wherein the transmitter is further configured to transmit, at the accesspoint, separate second responses to the respective probe requests to thewireless devices in the second portion, each of the second proberesponses transmitted according to the corresponding second modulationand coding scheme, and wherein the electronic hardware processor isfurther configured to utilize the modulation and coding schemes of proberesponses acknowledged by wireless devices of the plurality of wirelessdevices for subsequent communication with the wireless devices.
 4. Theapparatus of claim 3, wherein the transmitter is further configured totransmit the one or more frames by transmitting at least one of: abeacon, a short beacon, and a broadcast probe response.
 5. In acommunication system including at least an access point and a pluralityof wireless devices transmitting respective probe requests to the accesspoint for determining whether the access point is within a range forinitiating and maintaining a wireless communication link between each ofthe plurality of wireless devices and the access point, and the accesspoint transmitting a probe response frame including communicationparameters, a method for more efficient communication, the methodcomprising: receiving, at a wireless device of the plurality of wirelessdevices, one or more frames from the access point, each frame comprisinga transmission power indication; estimating a link quality based on theone or more transmission power indications; transmitting, at thewireless device, one of the respective probe requests using a firsttransmit power and a first modulation and coding scheme that is based onthe estimated link quality, the transmitted probe request including anindication of the first transmit power, the first modulation and codingscheme defining a first coding rate of the one respective probe request;and receiving, at the wireless device, the probe response frame based ona second modulation and coding scheme different from the firstmodulation and coding scheme and defining a second coding rate of theprobe response that is lower than the first coding rate.
 6. The methodof claim 5, wherein receiving the one or more frames comprise at leastone of: receiving a beacon, receiving a short beacon, and receiving abroadcast probe response.
 7. In a communication system including atleast an access point and a plurality of wireless devices transmittingrespective probe requests to the access point for determining whetherthe access point is within a range for initiating and maintaining awireless communication link between each of the plurality of wirelessdevices and the access point, and the access point transmitting a proberesponse frame including communication parameters, a device for moreefficient communication, comprising: a wireless device of the pluralityof wireless devices, the wireless device comprising: a receiverconfigured to receive one or more frames from the access point, eachframe comprising a transmission power indication; a processor configuredto estimate a link quality based on the one or more transmission powerindications; a transmitter configured to transmit one of the respectiveprobe requests using a first transmission power and a first modulationand coding scheme based on the estimated link quality, the transmittedprobe request including an indication of the first transmit power,wherein the first modulation and coding scheme defines a first codingrate of the one respective probe request, wherein the receiver isfurther configured to receive the probe response frame using a secondmodulation and coding scheme different from the first modulation andcoding scheme, the second modulation and coding scheme defining a secondcoding rate of the probe response frame that is lower than the firstcoding rate.
 8. The device of claim 7, wherein the receiver isconfigured to receive the one or more frames by receiving at least oneof: a beacon, a short beacon, and a broadcast probe response.
 9. Themethod of claim 1, wherein each of the respective probe requestsincludes a respective transmit power indication, and wherein thedetermination of the respective path-loss is further based on therespective transmit power indication.
 10. The apparatus of claim 3,wherein each of the respective probe requests includes a respectivetransmit power indication, and wherein the electronic hardware processoris further configured to determine the respective path-loss furtherbased on the respective transmit power indication.